Binocular

ABSTRACT

A binocular, including a right and left lens barrels respectively having a right and left telescope optical systems, is provided with a space occupied by a movement member that moves lenses to vary at least magnification so as to reduce the size of the binocular. First and second lens sliders, connected to a first and second lens, are moved along an optical axis direction of the telescope optical system so that the first and second lens, are moved along the optical axis direction. The first and second lens sliders move inside the space defined by the right and left telescope optical systems and a flat supporting plate.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a binocular, and moreparticularly, to a binocular including a compact optical arrangementstructure for varying magnification.

[0002] Some binoculars include “zooming” mechanisms capable ofcontinuously varying magnification.

[0003] During zooming, some of the optical systems in the two telescopesystems that form the binocular include two or more lenses for varyingmagnification. The lenses are moved along respective optical axes of thetwo binocular systems to different positions by means of a zoomingadjustment structure. The magnification lenses are sometimes included inthe eyepiece optical system, and change the focal lengths of theeyepiece optical system, thereby continuously varying the magnification

[0004] In some conventional zooming mechanisms, cam mechanisms fordriving the moving magnification lenses are provided in each of rightand left lens barrels, and cooperate with each other by means of adriving mechanism driven by (for example) a gear box.

[0005] However, the conventional zooming mechanism for a binocularoccupies a significant amount of space, so that it is difficult toefficiently accommodate the mechanism in a small size binocular. Thatis, a conventional zooming adjustment mechanism occupies enough space sothat it is difficult to make a smaller zooming binocular. Accordingly,zooming binoculars tend to be larger than a compact format, e.g., largerthan a compact binocular that may fit in a pocket or similar size.

SUMMARY OF THE INVENTION

[0006] It is therefore an object of the invention to reduce the size ofa binocular by reducing a space occupied by an optical arrangement unitthat moves the magnification varying lenses of the right and lefttelescope optical systems.

[0007] A binocular according to an embodiment of the invention includesan outer body housing, right and left lens barrels, and right and lefttelescope optical systems accommodated respectively in the right andleft lens barrels. A plurality of movable optical systems, provided in aportion of the telescope optical systems, are movable along an opticalaxis direction upon different moving conditions so that a magnificationof an observed image observed through the telescope optical systems isvaried and/or so that a focal distance of the image is changed.

[0008] A first movable optical system and a second movable opticalsystem are included in each the plurality of movable optical systems. Afirst guiding member guides and moves the first movable optical systemof each of right and left telescope optical systems, along the opticalaxis direction with a same respective right and left distance. A secondguiding member guides and moving the second movable optical system ofeach of right and left telescope optical systems, along the optical axisdirection with a same respective right and left distance. An arrangementstructure operates for moving the first and second movement member alongthe optical axis direction upon different moving conditions. Thearrangement structure is disposed between the right and left lensbarrels, and a supporting plate is disposed above or below the right andleft telescope optical systems with a predetermined space providedtherefrom, the supporting plate extending both in the optical axisdirection and in the lateral direction. The first and second guidingmembers are disposed and moved inside the space.

[0009] Optionally, the right and left lens barrels are movedsymmetrically with respect to a lateral direction center line of thesupporting plate in the right and left direction thereof.

[0010] Further, the first movement member may include a first arm memberformed of a pair of right and left arms, respectively extendingrightward and leftward, for engaging with the right and left firstmoving optical systems. In this case, the second movement member has asecond arm member formed of a pair of right and left arms, respectivelyextending rightward and leftward for engaging with the right and leftsecond moving optical systems.

[0011] Still further optionally, the first and second arms are parallelto each other inside the space and are approximately flush with eachother, portions of the first and second guiding members being flush witheach other, and the first and second arms are constituted to move alongthe optical axis direction upon different moving conditions so as not tointerfere with each other.

[0012] Optionally, the arrangement structure is provided with a bodydisposed in a center portion along the right and left directions of thebinocular, the body being provided with first and second connectingmembers formed for respectively connecting with the first and secondguiding members. The first guiding member includes a first center memberbetween the first arms, the first center member connecting to the firstconnecting member, and the second guiding member includes a secondcenter member between the second arms, the second center memberconnecting to the second connecting member. The first and secondconnecting members move along the optical axis direction upon differentmoving conditions.

[0013] Further, the arrangement structure includes a guide, the firstand second center members respectively have guided members that areguided by the guide for slidably moving along the optical axisdirection.

[0014] Still further, the first arm member is constituted in such amanner that each distance between the right and left guided members ofthe first arm member and right and left connecting portions that connectto the first moving optical systems respectively are equal to eachother.

[0015] Additionally, the second arm member is constituted in such amanner that each distance between the right and left guided members ofthe second arm member and right and left connecting portions thatconnect to the second moving optical systems respectively are equal toeach other.

[0016] Optionally, the first moving optical system is connected to thefirst arm member in such a manner that the first moving optical systemis movable laterally along the longitudinal direction of the first armmember, and the second moving optical system is connected to the secondarm member in such a manner that the second moving optical system ismovable laterally along the longitudinal direction of the second armmember.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

[0017] The present invention is further explained in the descriptionwhich follows with reference to the drawings, illustrating, by way ofnon-limiting examples, various embodiments of the invention, with likereference numerals representing similar parts throughout the severalviews.

[0018]FIG. 1A shows a plan view of a binocular according to anembodiment of the invention, in which right and left lens barrels are incontact with each other, and right and left eyepiece barrels arecontained inside a binocular body;

[0019]FIG. 1B shows a front view of the binocular of FIG. 1A seen fromthe direction of an arrow A1; and

[0020]FIG. 1C shows a side view of the binocular of FIG. 1A seen fromthe direction of an arrow A2.

[0021]FIG. 2A shows a bottom plan view of the binocular of FIG. 1A; and

[0022]FIG. 2B shows a rear plan view of FIG. 2A, seen from the directionof an arrow A3, of the binocular at the same configuration with FIG. 1.

[0023]FIG. 3A shows an upper plan view of the binocular according to anembodiment of the invention, in which the right and left lens barrelsare moved apart from each other as much as is permitted by themechanisms described herein, and in which the right and left eyepiecelens barrels are drawn from the respective lens barrels by as much as ispermitted by the mechanisms described herein;

[0024]FIG. 3B shows a front view of the configuration of FIG. 3A seenfrom the direction of arrow B1;

[0025]FIG. 3C shows a side view of the configuration of FIG. 3A seenfrom the direction of an arrow B2; and

[0026]FIG. 3D shows a side view of the configuration of FIG. 3A seenfrom the direction of an arrow B3.

[0027]FIG. 4A shows a bottom plan view of the binocular in the sameconfiguration as FIGS. 3A through 3D;

[0028]FIG. 4B shows a back view of the configuration of FIG. 4A seenfrom the direction of an arrow B4; and

[0029]FIG. 4C shows a side view of the configuration of FIG. 4A seenfrom the direction of an arrow B5.

[0030]FIG. 5 shows a partially cross-sectional top plan view of thebinocular.

[0031]FIG. 6 shows a cross-sectional view of FIG. 5 taken along a lineVI-VI.

[0032]FIG. 7 shows an exploded perspective view, illustrating anoverview of the binocular.

[0033]FIG. 8 shows an exploded perspective view, illustrating a portionof a supporting member shown in FIG. 7.

[0034]FIG. 9 shows an exploded perspective view, illustrating a portionof an optical arrangement unit and a supporting unit shown in FIG. 7.

[0035]FIG. 10 shows an exploded perspective view, illustrating thestructure of the optical arrangement unit shown in FIG. 7.

[0036]FIG. 11 shows an exploded perspective view, illustrating astructure of a portion of the optical arrangement unit and an upperplate shown in FIG. 7.

[0037]FIG. 12 shows an exploded perspective view, illustrating at leasta right outer unit of a right lens barrel.

[0038]FIG. 13 shows an exploded perspective view, illustrating at leasta right moving unit, a right objective unit and a right prism unit ofthe right lens barrel.

[0039]FIG. 14 shows an exploded perspective view, illustrating at leasta first lens unit, a second lens unit and an eyepiece unit of the rightlens barrel.

[0040]FIG. 15 shows an exploded perspective view, illustrating at leasta left outer unit of the left lens barrel.

[0041]FIG. 16 shows an exploded perspective view, illustrating at leastthe left moving unit, the objective unit, and the prism unit of the leftlens barrel.

[0042]FIG. 17 shows an exploded perspective view, illustrating at leastthe first lens unit, the second lens unit and the eyepiece unit of theleft lens barrel.

[0043]FIG. 18A shows a top plan view of a body of a supporting unit;

[0044]FIG. 18B shows a sectional view of FIG. 18A along the longitudinalline of the body; and

[0045]FIG. 18C shows a bottom plan view of the body.

[0046]FIG. 19A shows a sectional view of the body shown in the FIG. 18Bcut by a plane perpendicular to the longitudinal direction of the body,seen from the direction of arrow A; and

[0047]FIG. 19B is a sectional view of the body shown in the FIG. 18B cutby the plane perpendicular to the longitudinal direction of the body,seen from the direction of arrow A.

[0048]FIG. 20A shows a front plan view of a first lens slider;

[0049]FIG. 20B shows a top plan view of the first lens slider shown inFIG. 20A seen from the direction of arrow B;

[0050]FIG. 20C shows a bottom plan view of the first lens slider shownin FIG. 20A seen from the direction of arrow C; and

[0051]FIG. 20D shows a side plan view of the first lens slider shown inFIG. 20A seen from the direction of arrow D.

[0052]FIG. 21A shows a front plan view of a second lens slider;

[0053]FIG. 21B shows a top plan view of the second lens slider shown inFIG. 21A seen from the direction of arrow B; AND

[0054]FIG. 21C shows a bottom plan view of the second lens slider shownin FIG. 21A seen from the direction of arrow C.

[0055]FIG. 22 shows the bottom plan view of the optical arrangementunit, in which the first and second lens sliders part from each other atmaximum distance for arranging the telescope optical system to get thelowest magnification.

[0056]FIG. 23 shows the bottom plan view of the optical arrangementunit, in which the first and second lens sliders approach to each otherwith the nearest distance for arranging the telescope optical system toget the highest magnification.

[0057]FIGS. 24A and 24B are orthogonal views of the first and secondlens frames of FIG. 14, showing top and front views, respectively.

[0058]FIG. 25 shows a bottom plan view of the optical arrangement unit,with the user diopter adjustment in the center position, and showing themoving unit.

[0059]FIG. 26 shows a bottom plan view of the optical arrangement unit,with the user diopter adjustment in the extreme “+” position, andshowing the interaction of guiding grooves of the moving unit andengaging arms of the optical arrangement unit in a positioncorresponding to FIG. 22.

[0060]FIG. 27 shows a bottom plan view of the optical arrangement unit,with the user diopter adjustment in the extreme position, and showingthe interaction of guiding grooves of the moving unit and engaging armsof the optical arrangement unit in a position corresponding to FIG. 22.

DESCRIPTION OF THE EMBODIMENTS

[0061] Hereinafter, referring to the accompanying drawings, embodimentsaccording to the present invention will be described.

[0062] In the description, an objective side along an optical axis iscalled a “front side”, and an eyepiece side is called a “rear side”. Theterms “frontward” and “rearward” means respectively “toward the frontside” and “toward the rear side”. Right and left directions of thebinocular are defined by the orientations mentioned above, that is, theright and left sides of the binocular as used herein corresponds to thesides that a user of the binocular would consider his or her right andleft sides when operating the binocular. In general, as used herein, the“length” or optical axis direction is front to back or vice versa, the“width” or lateral direction is left to right or vice versa, and the“height” direction is top to bottom or vice versa.

[0063] First, referring to FIGS. 1 and 2, an overview of the binocularwill now be described.

[0064] A binocular 1000 includes a supporting unit 100 (see FIG. 3), anoptical arrangement unit 200, the right lens barrel 300 and the leftlens barrel.

[0065] The supporting unit 100 is provided between the right and leftlens barrels (300, 400), for supporting the right and left lens barrels(300, 400). The right and left lens barrels (300, 400) have respectivetelescope optical systems therein.

[0066] There are provided, at the supporting unit 100, a diopterdecorative ring 106 and an optical arrangement unit 200. The diopterdecorative ring 106 is provided on the bottom surface of the supportingunit 100, the surface of the diopter decorative ring 106 being exposed,i.e., facing outward. The optical arrangement unit 200 includes a focusarrangement ring 202 for arranging or adjusting focus of the binocular,and a zooming operation ring 204 for setting and adjusting magnificationof both of the right and left telescope optical systems.

[0067] The right and left lens barrels (300, 400) are supported by thesupporting unit 100 therebetween, and are movable in the width directionof the binocular 1000, or the lateral direction. The right lens barrel300 and the left lens barrel 400 cooperate to simultaneously movesymmetrically to the center line of the supporting unit 100.

[0068] The right and left lens barrels (300, 400) include respectively aright moving unit 303 (shown in FIG. 5)and a left moving unit 403 (shownin FIG. 7), and respectively a right eye piece cylinder 304 and a lefteyepiece cylinder 404. The right moving unit 303 holds a right eyepiecelens unit 309 and a right erecting prism unit 306. The left moving unit403 holds a left eyepiece lens unit 409 and a left erecting prism unit406.

[0069] If the focus arrangement ring 202 is rotated, the right and leftmoving unit (303, 304) and the right and left eyepiece cylinder (304,404) are moved for focus arrangement.

[0070] If the zooming operation ring 204 is rotated, some pieces of theoptical structure, included both in the right and left lens barrel (300,400) and as described herein, are moved along the optical axis forvarying the magnification. The mechanism for varying the magnificationis described in a later portion of this specification.

[0071] The focus arrangement ring 202 and the zooming arrangement ring204 are disposed near to the rear end (i. e. near to the eyepiececylinder) of the binocular 1000 along the center line. The focusarrangement ring 202 and the zooming arrangement ring 204 are coaxialand adjacent to one another, in this order from the front end, and areeach rotatable about an axis parallel to the optical axes. The focusarrangement ring 202 and the zooming arrangement ring 204 are disposedfacing outward from the upper surface of the supporting unit 100. Here,the axis mentioned above, about which the focus arrangement ring 202 andzooming arrangement ring 204 are rotated, is parallel to the opticalaxes of each of the right and left telescope optical systems 300,400.Accordingly, hereinafter, the “axis direction” is parallel to theoptical axis direction, unless otherwise specified.

[0072] In the following description, the structures of each operationalunit of the binocular 1000 are described.

[0073]FIG. 5 shows a partially cross-sectioned top plan view of thebinocular 1000, FIG. 6 shows a cross-sectioned view of FIG. 5 along aline VI-VI of FIG. 5, and FIG. 7 shows an exploded perspective viewillustrating an overview of the binocular assembly.

[0074]FIG. 8 shows an exploded perspective view illustrating a portionof a supporting member, FIG. 9 shows an exploded perspective viewillustrating a portion of an optical arrangement unit 200 and thesupporting unit 100, FIG. 10 shows an exploded perspective viewillustrating the structure of the optical arrangement unit 200, and FIG.11 shows an exploded perspective view illustrating a structure of aportion of the optical arrangement unit and an upper plate.

[0075]FIG. 12 shows an exploded perspective view illustrating mainly astructure of a right outer unit of the right lens barrel FIG. 13 showsan exploded perspective view illustrating mainly a structure of a rightmoving unit, a right objective unit and a right prism unit of the rightlens barrel, FIG. 14 shows an exploded perspective view illustratingmainly a structure of a first lens unit, a second lens unit and aneyepiece unit of the right lens barrel.

[0076]FIG. 15 shows an exploded perspective view illustrating mainly astructure of a left outer unit of the left lens barrel, FIG. 16 shows anexploded perspective view mainly of the structure of the objective unit,the first lens unit and the second lens unit of the left lens barrel,FIG. 17 shows an exploded perspective view of mainly the structure ofthe first lens unit, the second lens unit and the eyepiece unit of theleft lens barrel.

[0077]FIG. 18A through 18C show a body 101 of the supporting unit 100.FIG. 18A shows a plan (top) view of the body 101; FIG. 18B shows asectioned view along a vertical plane perpendicular to the longitudinaldirection of the body 101; and FIG. 18C is a bottom view of the body101. FIG. 19A and 19B are sectioned views along a vertical planeperpendicular to the longitudinal direction in FIG. 18B, FIG. 19A beingseen from the direction of the arrow A in FIG. 18B and FIG. 19B fromdirection of the arrow B in FIG. 18B.

[0078]FIGS. 20A through 20D show a first lens slider 213. FIG. 20A showsa partially sectioned front view of the lens first slider 213; FIG. 20Bshows a plan view of the first lens slider 213 of FIG. 20A, seen fromthe direction of the arrow B; and FIG. 20C shows a bottom view of thefirst slider 213 of FIG. 20A, seen from the direction of the arrow C.FIG. 20D shows a side view of the first lens slider of FIG. 20A seenfrom direction of the arrow D.

[0079]FIGS. 21A through 21C show orthogonal views of a second lensslider 214. FIG. 21A is a partially sectioned front view of the secondlens slider 214; FIG. 21B is a plan view of the second lens slider 214of FIG. 21A, seen from the direction of an arrow B; and FIG. 21C is abottom view of the second lens slider 214 of FIG. 21, seen from thedirection of arrow C.

[0080] Referring to the FIGS. 7 to 11, the structures of the supportingunit 100 and the optical arrangement unit 200 will now be described.

[0081] As shown in FIGS. 7 through 11, the supporting unit 100 includesa body 101 (shown in FIGS. 9 and 10, corresponding to a body in theclaims), a supporting plate 102 (shown in FIGS. 7 and 8, correspondingto a supporting plate in the claims), a bottom lid 103 (shown in FIGS. 7through 9), an upper plate 104 (shown in FIGS. 7 and 11), a pinion gear105, a right cooperation plate 109, a left cooperation plate 110 andother parts as described below. The bottom lid 103 is provided with thediopter decorative ring 106 and a diopter arranging eccentric seat 107that constitute the diopter correction unit, which is described below.

[0082] The supporting plate 102 is formed in a generally rectangularshape, and has longitudinal sides that are substantially parallel to afront and a rear edge lines of the binocular 1000. The right and leftsides of the supporting plate 102 are parallel to the right and leftsides of the binocular 1000 .

[0083] As shown in FIG. 8, two protrusions 102A1 and 102A2 are formeddisposed in the vicinity of the upper right edge portion, near to thefront corner and rear corner, respectively, of the supporting plate 102.Similarly, two protrusions 102B1 and 102B2 are formed disposed in thevicinity of the upper left edge portion, near to the front corner andrear corner, respectively, of the supporting plate 102.

[0084] Two protrusion 102B3 and 102A3 are formed in this order from thefront side of the supporting plate 102 and projecting therefrom, andpositioned approximately on the binocular center line between thelateral sides on the supporting plate 102. A circular opening 102C isformed between the front protrusion 102B3 and the front edge, and athreaded hole 102D is formed (penetrating the supporting plate 102)between the two protrusions 102B3 and 102A3.

[0085] Two engaging grooves 102H1 and 102I1 are formed (penetrating thesupporting plate 102 in the height direction)), extending near to andparallel to the front edge of the supporting plate 102. The engaginggroves 102H1 and 102I1 are formed symmetrically with respect to thecenter of the width of the binocular 1000. Similarly, two engaginggrooves 102H2 and 102I2 are formed (penetrating the supporting plate 102in the height direction), extending near to and parallel to the rearedge of the supporting plate 102. The engaging groves 102H2 and 102I2are also formed symmetrically with respect to the center of the width ofthe binocular 1000.

[0086] Two notches 102J1 and 102J2 are cut disposed at a predetermineddistance along the right edge of the supporting plate 102, near to thefront and rear edge, respectively, and opening to the right. Two notches102K1 and 102K2 are provided similarly at the left edge disposed at apredetermined distance along the left edge of the supporting plate 103and opening to the left.

[0087] A right slide plate 109 includes a rectangular body 109A, and anextending member 109B extending from the rectangular body 109A. Twoguiding grooves 109A1 and 109A2 are formed near to front and rear edgeof the rectangular body 109A, extending in the width or lateraldirection, so as to receive the projections 102A1 and 102A2 penetratingtherethrough. A guiding groove 109B1 is formed on the extending member109B, extending laterally, to receive the projection 102A3 penetratingtherethrough.

[0088] Two threaded holes 109C1 and 109C2 are provided, penetrating theright slide plate 109, respectively positioned at the front and rearcorners of the left side of the body 109A of the right slide plate 109,and two threaded holes 109Dl and 109D2 are provided, penetrating theright slide plate 109, respectively positioned at the front and rearcorners of the right side of the body 109A of the right slide plate 109.The threaded holes 109C1 and 109C2 are disposed with the same distancetherebetween as is between the guiding grooves 102H1 and 102H2, and thethrough hole 109Dl and 109D2 are disposed with the same distancetherebetween as is between the notches 102J1 and 102J2 on the supportingplate.

[0089] The left slide plate 110 includes a rectangular body 110A, and anextending member 110B extending from the rectangular body 110A. Twoguiding grooves 110A1 and 110A2 are formed near to the front and rearedges of the rectangular body 110A, extending laterally or in the widthdirection, so as to receive the projections 102Bl and 102B2 penetratingtherethrough. A guiding groove 110B1 is formed on the extending member10B, extending laterally, to receive the projection 102A3 penetratingtherethrough.

[0090] Two threaded holes 110C1 and 110C2 are provided, penetrating theleft slide plate 110, respectively positioned at the front and rearcorners of the left side of the body 110A of the left slide plate 110,and two threaded holes 110D1 and 110D2 are provided, penetrating theleft slide plate 110, respectively positioned at the front and rearcorners of the left side of the body 110A of the left slide plate 110.The threaded holes 110C1 and 110C2 are disposed with the same distancetherebetween as is between the guiding grooves 102I1 and 102I2, and thethrough hole 110D1 and 110D2 are disposed with the same distancetherebetween as is between the notches 102K1 and 102K2 on the supportingplate.

[0091] A right rack 109B2 and a left rack 110B2 are providedrespectively at the front edge of the extending member 109B of the rightslide plate 109, and at the rear edge of the extending member 110B ofthe left slide plate 110. the right rack 109B2 and left rack 110B2extend laterally, in the width direction, toward the center of thebinocular 1000.

[0092] The right slide plate 109 is slidably supported on the supportingplate 102, with each guiding grooves 109A, 109A2 and 109B1 havinginserted therethrough, respectively, the projections 102A1, 102A2 and102A3, each of which has a threaded hole formed thereon. In this manner,screws 802 are engaged to the threaded holes having intervening washers801 .

[0093] The left slide plate 110, similarly, has the guiding groove110A1, 110A2 and 110B1 having inserted therethrough, respectively, theprojections 102B1, 102B2 and 102B3s each of which has a screw engaging athreaded hole and intervening washers 801.

[0094] A pinion gear 105 is disposed between the right and left rack109B2, 110B2 so as to mesh with the two racks 109B2, 110B2. The shaftportion of a screw 803 penetrates the threaded hole 102D on thesupporting plate 102 from the underside thereof and also penetrates acenter hole of the gear 105, ultimately engaging a threaded hole 103A ofthe bottom lid 103.

[0095] The position and arrangement of the bottom lid 103 are shown inFIGS. 7 and 8. The bottom lid 103 is a rectangular-shaped plate, havinga longitudinal direction and extending in the optical axis direction,and being supported above the supporting plate 102. The bottom lid 103and the supporting plate 102 are positioned on either side (top andbottom, respectively) of the extending portion 109B of the right slideplate 109 and the extending portion 110B of the left slide plate 110.Further, the bottom lid 103 is positioned between the under surface ofthe body 101 and upper surface of the supporting plate 102 in a mannerdetailed below.

[0096] The position of bottom lid 103 with respect to the supportingplate 102 is determined as described herein. Edge portions 103B (theright side edge portion 103B being hidden in FIG. 8) formed on the rightand left front edges are inserted into the grooves 102E extending alongthe optical direction, on both right and left edges of the supportingplate 102. Accordingly, notches 103C formed at the rear right and leftedges of the bottom lid 103 are fitted into the projections 102F formedat the rear right and left edges, symmetrically formed with respect tothe width direction, on the upper surface of the supporting plate 102.Accordingly, the bottom lid 103 is positioned on the supporting plate102. In the center of the projection 102F is formed a threaded throughhole 102G, through which a screw 806 is inserted. It should be notedthat throughout the drawings, the various screws (including the screw806 and various other screws) are exaggerated in scale to aid review ofthe drawings.

[0097] In the bottom lid 103 are formed four protrusions 103D projectingdownward in the height direction. A center portion of each protrusion103D is curved downward, i.e., having a lowest point in the lateralcenter, so that the protrusions 103D exhibit a curved plane (arcing fromleft to right) extending perpendicular to the longitudinal direction ofthe bottom lid 103. These four protrusions 103D press the upper surfaceof the extending portion 109B of the right slide plate 109 and theextending portion 110B of the left slide plate 110 (i.e., the rear twoprotrusions 103D press on the right side plate 109, while the front twoprotrusions 103D press on the left side plate 110) to create frictionforce when the right and left slide plates 109 and 110 are movedlaterally. This friction force gives a better operation feeling to theoptical barrels 300 and 400 slide laterally, as detailed below.

[0098] With the above constitution, the rack 109B2 of the right slideplate 109 and the rack 110B2 of the left slide plate 110 mesh with thepinion gear 105, so that the right slide plate 109 and left slide plate110 slide toward and away from each other in the lateral direction.Moreover, since the racks 109B2, 110B2 and the pinion gear 105 have thesame tooth pitch for engagement, the right slide plate 109 and leftslide plate 110 simultaneously move the same distance in the oppositedirection (with respect to each other).

[0099] A through hole 103G is formed in an area surrounded by the rightand left protrusions 103B, at the front part of the bottom lid 103.

[0100] A user diopter adjustment mechanism is shown in FIGS. 6 through9. As shown in FIGS. 4A, 6, 7, and 25 through 27 the diopter decorativering 106 has a disc-shaped diopter correction body 106A having a discdiameter that is larger than that of the through hole 103G, a shaftportion projected from the upper center of the body 106A, and a threadedhole that is formed on the shaft portion, and having an axis parallel tothat of the shaft portion. Indicia for the extreme “+” position 106G,the middle position 106F, and the extreme “−” position 106H are providedon the diopter correction body 106A. As shown in FIGS. 6 and 7, thediopter decorative ring 106 engages a diopter eccentric seat 107.

[0101] The diopter is corrected by rotating the body 106A about the axisof the shaft portion, as detailed below, which in turn rotatesprotrusions 107C of the diopter eccentric seat 107 that engage slots(not shown) in the diopter decorative ring, and thereby the entirediopter eccentric seat 107. Two engaging protrusions 107C are providedon opposite sides of the eccentric axis of the diopter eccentric seat107, for engaging two engaging slots (not shown) of the diopterdecorative ring 106. Here, even if only one engaging slot andcorresponding protrusions 107C of the diopter eccentric seat 107 engage,the mechanism can correct the diopter; that is, engagement via only oneengaging slot and only one corresponding protrusion 107C may beconsidered equivalent, although engagement of two portions provides morepositive driving.

[0102] As shown in FIGS. 6, 7, and 9, the diopter eccentric seat 107 isprovided with a disk-shaped body 107A (corresponding to a firsteccentric portion of a first eccentric member) having a disc diameterthat is larger than the inner diameter of the through hole 103G, aneccentric hole 107B penetrating the disk-shaped body 107A in the heightdirection, with a predetermined eccentricity relative to a center of thebody 107A, and the two protrusions 107C which are inserted to the twoengaging slots of the diopter decorative ring 106.

[0103] As assembled, the shaft portion of the diopter decorative ring106 penetrates the through hole 103G from the under side of the bottomlid 103, and is inserted into the eccentric hole 107B of the dioptereccentric seat 107. The two protrusions 107C of the diopter eccentricseat 107 are inserted into the two engaging slots of the diopterdecorative ring 106. As shown in FIGS. 6 through 8, a screw 805, havinga spring washer 804, is inserted through the eccentric hole 107B of thediopter eccentric seat 107 and affixed, so that the shaft portion of thescrew 805 is screw coupled into the threaded hole formed at the shaftportion of the diopter decorative ring 106, fixing the diopter eccentricseat 107 on the diopter decorative ring 106 via the bottom lid 103.

[0104] In such a constitution, as shown in FIG. 6, the body 106A of thediopter decorative ring 106 is exposed (downward from the bottom surfaceof the supporting plate 102) through the through hole 102C. The diopterdecorative ring 106, coupled with the diopter eccentric seat 107, isdisposed at the center in the width direction of the binocular 1000 andnear to the front end of the binocular 1000.

[0105] Referring to FIG. 6, the periphery of the trough hole 103G underthe bottom lid 103 is formed with a protrusion 103J in the peripheraldirection (hidden in FIG. 6). The protrusion 103J engages with a curvedchannel 106E on the upper portion of the diopter decorative ring 106while engaged, so that the end of the peripheral curved channel 106E ofthe diopter decorative ring 106 abuts the end of the peripheralprotrusion 103J for controlling the amount of the rotation of thediopter decorative ring 106.

[0106] The diopter decorative ring 106 and the diopter correctioneccentric seat 107 are integrally fixed in the rotation direction of theshaft 106B, by the engagement between the concaved portion 106D and theprotrusions 107C, but are slightly movable in the shaft direction of theshaft portion 106B so as to permit detent “clicking” as described below.

[0107] Referring to FIG. 6, an engagement portion 103H composed of aplurality of detent knurled portions extends about the peripheraldirection of the through hole 103G, formed at the peripheral portion ofthe through hole 103G of the upper surface of the bottom lid 103.Further, a protrusion or set of protrusions (hidden in FIG. 6) formedunder the surface of the diopter eccentric seat 107 engages the engagingportion 103H. Accordingly, the protrusion(s) “clicks” with the engagingportion 103H, while the diopter decorative ring 106 is rotated, giving acomfortable operational clicking feeling (tactile and/or auditoryfeedback) thereby. In this operation, the spring washer 804 presses theunder surface of the body 107A and the protrusions 107D of the dioptereccentric seat 107 onto the engaging portion 103H to provide sufficientplay to permit the “clicking” engagement without excessive tightness orjamming.

[0108] As shown in FIG. 9, 10, 18A through 18C and 19A, 19B, the body101 of the supporting unit 100 is provided with a front wall 101A, arear wall 101B, a right wall 101C and a left wall 101D that connect theright and left side of the front and rear wall 101A and 101B. The upperand under portion of the body 101 is open to the top side in arectangular shape.

[0109] The underside of the body 101, being covered by the bottom lid103, is coupled onto the supporting plate 102. Four screws 806 areinserted through four screw holes 102G formed on the supporting plate102, to be screw coupled to the four threaded holes 101E formed at theunder side of the body 101.

[0110] As shown in FIGS. 7 and 11, the upper plate 104 is formed in agenerally rectangular shape and is of and approximately the same size asthe supporting plate 102,andcovers the upper part of the body, whenattached. Openings 104B and 104C are formed in the center in the widthdirection near to the rear end of the binocular, so that a portion ofeach of the focus arrangement ring 202 and zooming arrangement ring 204,respectively, which are accommodated therein, are exposed therethrough.

[0111] Rectangular shaped decorative plates 101I and face plate 101J arerespectively attached to the front side of the front wall 101A and therear side of the rear wall 101B.

[0112] In the supporting portion 100 mentioned above, the body 101,supporting plate 102, bottom lid 103 and the upper plate 104 areintegrally fixed. The right slide plate 109 and left slide plate 110 aresupported slidably in the width direction by the supporting plate 102.

[0113] The optical arrangement unit 200, shown in FIGS. 7, 10, 11, isdescribed below.

[0114] Referring to both FIGS. 10 and 11, the optical arrangement unit200 is provided with a body 101 (FIG. 10), a main shaft 201 (FIGS. 10and 11), a focus arrangement ring 202 (FIGS. 10 and 11), a zoomingarrangement ring 204 (FIG. 11), a movement shaft 206 (FIGS. 10 and 11),a cam ring 207 (FIGS. 10 and 11), a first lens guiding piece 208 (FIGS.7, 10, and 11, corresponding to a first connecting member in theclaims), a second lens guiding piece 209 (FIGS. 7 and 11, correspondingto a second connecting member in the claims), a cam frame 210 (FIG. 11),a guiding piece shaft 211 and 212 (FIG. 11), a first lens slider 213(FIGS. 7, 10 and 20A through 20D, corresponding to a first guidingmember in the claims), a second lens slider 214 (FIGS. 7, 10 and 21Athrough 21C, corresponding to a second guiding member in the claims) apressing plate 215 (FIG. 10), a cooperation shaft 216 (FIG. 10) andadditional parts as discussed below.

[0115] The main shaft 201 extends parallel to the optical axis of thelens barrels 300 and 400. The front and rear ends of the main shaft 201are supported respectively by axle bearings provided on the front wall101A and rear wall 101B of the body 101. The main shaft 201 rotatablysupports the focus arrangement ring 202 and the zooming arrangement ring204, as detailed below. The diopter decorative ring 106 is rotatablydisposed about an axis perpendicular to the axis of the main shaft 201.

[0116] On the outer peripheral surface of the front end portion, splines201A are formed extending along the axis direction, disposed at apredetermined distance about the periphery of the front end portion ofthe main shaft 201 and extending for a predetermined distance along thefront end portion of the main shaft 201. These splines 201A are insertedinto matching grooves 207B formed in a hole 207A of the cam ring 207.

[0117] The zooming arrangement ring 204 includes a ring-shaped body 204Ad and a rubber ring 204B covering the outer periphery of the body 204A.

[0118] The body 204A includes a hole A1 having an inner bore throughwhich the rear portion of the main shaft 201 is inserted, the body 204Abeing coupled to the main shaft 201. A screw 808 screw-couples the body204A to the rear portion of the main shaft 201 from the rear side.

[0119] The cam ring 207, a cylindrically shaped cam with an outer wall,having a width in the peripheral direction and a length in the axisdirection, includes a hole 207A formed on the outer wall. The hole 207Ais provided with the grooves 207B formed along the diameter for engagingthe splines 201A of the main shaft 201. In such a manner, the cam ring207 is supported by the main shaft 201 to slide along the axis, but isnot rotatable around the main shaft 201. The outer peripheral surface207C of the cam ring 207 is provided with two first cam grooves 207D andtwo second cam grooves 207E formed about the outer peripheral surface207C.

[0120] The moving shaft 206 includes a first shaft portion 206A providedat the rear portion thereof, a second shaft portion 206B at the frontportion thereof, a flange 206C formed between the first and second shaftportion, and a hole 206D penetrating the first shaft portion 206A, theflange 206C and the second shaft portion 206B and extending along theaxis of the moving shaft 206. The inner diameter of the hole 206D isformed so that the main shaft 201 is rotatable while insertedtherethrough.

[0121] A helical guiding groove 206A1 is formed on the outer peripheralsurface of the first shaft portion 206. The guiding groove 206A1includes a first groove portion 296A11 with a wide pitch along the shaftdirection, and a second groove portion 206A12 with a narrow pitch inthis order toward the object side.

[0122] The focus arrangement ring 202 includes a ring body 202A and arubber ring 202B, the rubber ring covering the circumference of the body202A. The diameters of the focus arrangement ring 202 and zoomingarrangement ring 204 are formed to be approximately the same size. Thatis, the outer diameters of the rubber ring 202B and 204B have nearly thesame size.

[0123] The inner peripheral surface 202A1 of the body 202A has two ballholders 202A11 formed therein on the opposite positions in the diameterdirection to hold two balls 203, in a manner such that the two balls canrotate but are not movable in the diameter direction.

[0124] An arm 202A1 is integrally formed on the body 202A (shown in FIG.11), extending in the diameter direction, to rotate when the focusarrangement ring is rotated. The balls 203 engaged in the engagementportion 202A11 on the arm 202A1, in such a case, moves along the helicalguiding groove 206A1 formed in the first shaft portion 206A of themoving shaft 206, the helical guiding groove 206A1 being formed “doubledscrewed”, i.e., having a thread pitch that changes from coarser to fineralong its length, on the first shaft 206A of the moving shaft 206.

[0125] As shown in FIG. 11, when the balls 203 engage the first groove206A11 (with a wide/coarser pitch), the moving amount of the movingshaft by rotation of the focus rotation ring 202 is larger than thatwhen engaging the second groove 206A12 (with a narrow/finer pitch).

[0126] The cam frame 210, shown in FIG. 11, is a substantiallyring-shaped frame, having an inner portion 210A. Both of the upper sidesof the inner portion 210A hold a shaft (numbered 211, 212 on right andleft sides) extending parallel to the optical axis. The circumference ofeach shaft 211, 212 faces the center axis of the cam frame 210. Thefirst lens guiding piece 208 and the second lens guiding piece 209,respectively, are slidably held on shafts 211, 212.

[0127] The main shaft 201 is inserted in a hole 207A of the cam ring207, and the cam ring 207 axially and slidably supported by the mainshaft 201. The cam ring 207 is rotatably supported by the second shaftportion 206B of the movement shaft 206 such that the cam ring 207 isrotatable relative to, but fixed axially with respect to, the secondshaft portion 206B. A bayonet-type engagement formed on the second shaftportion 206B near the flange 206C and on the rear of the cam ring 207 isemployed for this purpose, although other structures would serve aswell. Accordingly, the cam ring 207 is supported by the main shaft 201,and with respect to the main shaft 201, is not rotatable but is movablein the axial (optical axis) direction.

[0128] The cam frame 210, accommodating the cam ring 207, is coupled tothe flange 206C of the moving shaft 206 by three screws 809, so that thecam frame 210 and the moving shaft 206 are integrally fixed.

[0129] The substantially cylindrical inner portion 210A has a right arm210C1 on the right side of the cam frame 210, and a left arm 210C2 onthe left side of the cam frame 210. The rear portions of the right andleft arms 210C1 and 210C2 are respectively provided with threaded holes210C11 and 210C21 opening rearward. In addition, a rear part of aconnecting arm 210D facing rearward has a threaded hole formed therein(not shown), the threaded hole that is opening toward the rear of thebinocular 1000. Threaded holes 210C11, 210C21 and the threaded holeopening to the rear are screw coupled by screws 809 that are insertedthrough the through holes 206C1, 206C2 and 206C3 provided on the flange206C of the moving shaft 206, so that the cam frame 21 is fixed to themoving shaft 206. Moreover, the rear end of the connecting arm 210D hasa threaded hole 210D1 formed therein facing downward.

[0130] Protrusions 206C4, 206C5 (shown in FIG. 11) are formed on theright and left portion of the flange 206C of the moving shaft 206.

[0131] The protrusions 206C4, 206C5 are arranged to engage and movealong guiding grooves 101C11 and 101D11 (shown in FIG. 9, and in detailin FIG. 18A-18C and 19A, 19B) extending along the right and left walls101C and 101D. The engagement of the protrusions 206C4, 206C5 with theguiding grooves 101C11, 101D11 renders the moving shaft 203 (and camframe 210, integrally attached thereto) movable in the direction of theoptical axis, but not rotatable about the optical axis direction.

[0132] The cam frame 210 (FIG. 11) is supported by the inner surface101C of the right wall 101C (FIG. 10) and the inner surface 101D of theleft wall 101D of the body 101, in such a manner that the cam frame 210is movable in the direction of the optical axes, but is not rotatableabout the axis direction of the main shaft.

[0133] As shown in FIGS. 10 and 11, protrusions 206C4 and 206C5respectively protrude from the right and left edges of the flange 206Cof the moving shaft 206. As shown in FIGS. 18A-18C and 19A, 19B, thebody 101 is provided with guiding grooves 101C11 and 101D11 extending inthe direction of the optical axes, respectively on the upper edge of theinner surface 101C1 of the right wall 101C and the upper edge of theinner surface 101D1 of the left wall 101D.

[0134] The protrusions 206C4, 206C5 of the moving shaft 206 engage andare slidably supported by the guiding grooves 101C11 and 101D11 to slidein the direction of the optical axes, such that the moving shaft 206 andcam frame 210 are movable in the optical axis direction, but are notrotatable about the direction of the axis of the main shaft 201.

[0135] When assembled, each protrusion 206C1 and 206C2 abuts arespective bank 101C12 and 101D12 (shown in FIGS. 9, 10, 18A, and 18B)for restricting the front range of the moving shaft 206. Moreover, eachprotrusion 206C4 and 206C5 abuts the front surface of the rear wall101G1 (shown in FIGS. 9 and 10) of the body 101 for restricting the rearmovable range.

[0136] As assembled, the second shaft portion 206B of the main shaft 201is inserted in a hole 207A of the cam ring 207, and the cam ring207 isrotatably supported by the second shaft portion 206B.

[0137] As shown in FIGS. 18B and 18C, the body 101 is provided with twoguiding portions 101C2 and 101D2 (corresponding to a guide, or right andleft guides, in the claims) formed on the lower edges of the right wall101C and left wall 101D at the area exposing downward therefrom. Theguiding portions 101C2 and 101D2 are provided with ridges extendingalong the optical axis direction, disposed with a predetermined distancetherebetween in the width (left to right) direction.

[0138] Two ridges, one formed on each of protrusions 101C2 and 101D2,are formed to engage and guide the first and second lens sliders 213(via guided portions 213E, 213F) and 214 (via guided portions 214E,214F), to be movable in the direction of the optical axes, but notmovable in any direction perpendicular to the optical axis direction.

[0139] The cam ring 207 has first cam grooves 207D and second camgrooves 207E formed therein.

[0140] As shown in FIGS. 10 and 11, the second lens guiding piece 209has two holding surfaces therein that are spherically concave so as tohold two balls 210B, the two balls 210B being rotatably engaged in thegrooves 207E of the cam ring 207. The first lens guiding piece 208 hastwo similar holding surfaces therein (hidden in FIGS. 10 and 11) thatare shaped spherically concave so as to hold another two balls 210B, theadditional two balls 201B being rotatably engaged in the grooves 207D ofthe cam ring 207.

[0141] When the cam ring 207, held by the cam frame 210, is rotated bythe rotation of the main shaft 201, the first and second cam grooves207D and 207E of the cam ring 207 rotate with respect to the cam frame210. This rotation movement makes the first and second lens guidingpieces 208 and 209 move along the axial direction. Here, the first andsecond lens guiding pieces are disposed at both sides of the cam frame210, facing each other and containing the cam ring 207, so that theymove in the opposite directions with respect to each other along theoptical axis. That results in the movable ranges of the first and secondlens guiding pieces overlapping in the axial direction of the main shaft201.

[0142] The pressing plate 215 is a rectangular-shaped plate, providedwith a through hole 215B in the height direction. A screw 810, insertedthrough the through hole 215B, engages the bottom wall of the cam frame210 so that the pressing plate 215 is attached to the cam frame 210.That is, the pressing plate 215 moves, at least with respect to movementalong the optical axis, integrally with the moving shaft 206, the camring 207 and the cam frame 210 (although certain of these members arerotatable with respect to one another as set forth herein). The firstand second lens slide plates 213 and 214 are intermediate the pressingplate 215 and the bottom wall of the main body 101. Protrusions on theupper rear side of the pressing plate 215 maintain a clearance in whichthe slide plates 213 and 214 are movable in front and rear directions.

[0143] As shown in FIGS. 9 and 10, and with reference to FIG. 21, afirst lens slide plate 213 is screw coupled to the first lens guidingpiece 208 by a screw 811, and is integrally movable with the first lensguiding piece 208. In a similar fashion, the second lens slide plate 214is screw coupled to the second lens guiding piece 209 (as shown in FIG.11) by a screw 812, and is integrally movable with the second lensguiding piece 209.

[0144] It should be noted that some of the assemblies described hereinare described and/or claimed as two separate elements. For example, twoelements so described are the first lens slide plate 213 and the firstlens guiding piece 208, screw coupled to one another. In this example,although construction may be more difficult, the first lens slide plate213 and first lens guiding piece 208 maybe constituted as one solidpiece, and where the language of the claims describes both parts 213 and208 as separate elements, the present invention as claimed nonethelessencompasses such equivalent one piece structures.

[0145] At the same time, where two (or more) piece assemblies have aparticular advantage for the purpose of ease of construction or otheradvantages, the distinctiveness of two-piece assemblies is notdisclaimed as part of the invention. For example, ease of constructionis important in the manufacturing of a binocular, and such separation ofelements facilitates such construction, or can make constructionpossible where a one-piece construction would be impossible toimplement. This principle applies to the slide plates 213, 214 and lensguiding pieces 208, 209, and to other structures described herein, thathave one or more advantages when constituted as separate elements (suchas the advantage of facilitating construction) and would be recognizedas having such advantages by one skilled in the art, even where notexplicitly so noted.

[0146] The first lens slide plate 213 is formed in one piece by a firstcenter portion 213A and a first arm 213B. The first center portion 213Ais a rectangular-shaped plate to be connected to the first lens guidingpiece 208, and the first arm 213B is first bent downward from the rightand left sides of the first center 213A and is then bent to extendhorizontally, laterally and linearly.

[0147] The first center portion 213A is provided with an engagementportion 213C for engaging the engaging portion 208A of the first lensguiding piece 208, the engagement portion 213C having a through holethrough which the screw 811 is inserted and screw-couples the engagingportion 208A.

[0148] Guided portions 213E, 213F includes a protrusion extending alongthe direction of the optical axes at the region where the right and leftfirst arm 213B connect to the first center portion 213A. The right andleft first arm portion 213B extend laterally from the guided portions213E, 213F. These guided portions 213E, 213F are movably supported bythe guiding portion 101C2 and 101D2 of the body 101, to be movable alongthe optical axis direction.

[0149] The first center portion 213A is supported to move in the opticalaxis direction, with the upper and lower surfaces of the first centerportion 213A (in the height direction) being pressed respectively by thepressing plate 215 and by the bottom of the body 101.

[0150] The right and left ends of the engaging arm 213B are provided,respectively, with channel grooves 213D formed extending laterallyoutward, the channel grooves 213D being engaged slidably with a firstlens unit 307 (shown in FIG. 14) and 407 (shown in FIG. 17) of the rightand left telescope optical system, slidable in the lateral direction.

[0151] As shown in FIGS. 21A through 21C, a second lens slide plate 214is formed in one piece of a second center portion 214A and two secondarms 214B. The second center portion 214A is a substantiallyrectangularly shaped plate to be connected to the second lens guidingpiece 209, and the second arm 214B is first bent downward from the rightand left sides of the second center plate 213A and is then bent toextend horizontally, laterally and linearly.

[0152] The second center plate 214A is provided with an extension 214A1extending toward the front of the binocular 1000, where an engagementportion 214C is formed for engaging the engaging portion 209A of thefirst lens guiding piece 209. The engagement portion 214C has a throughhole through which the screw 811 is inserted and screw-couples theengaging portion 209A of the second lens guiding piece 209. The rearbottom surface of the extension 214A connects to and is substantiallyflush with the upper surface of the second center portion 214A.

[0153] Guided portions 214E, 214F include protrusions extending parallelto the optical axis at the area where the right and left second arms214B connect to the second center portion 214A. The right and leftsecond arm portions 214B extend laterally from the guided portions 214E,214F.

[0154] These guided portions 214E, 214F are movably supported by theguiding portion 101C2 and 101D2 of the body 101, movable along theoptical axis direction.

[0155] The second center portion 214A is supported to be movable in theoptical axis direction, with its upper and lower surfaces in the heightdirection being pressed respectively by the pressing plate 215 and bythe bottom of the body 101.

[0156] The right and left ends of the engaging arm 214B are respectivelyprovided with channel grooves 214D formed extending laterally outward,the channel grooves 214D being engaged slidably with a second lens unit308 (as shown in FIG. 14) and 408 (as shown in FIG. 17) of the right andleft telescope optical system, slidable in the lateral direction.

[0157] The first and second lens sliders 213 and 214 are disposed inthis order along the optical axis, and are intermediate the pressingplate 215 and the bottom of the body 101, wherein the upper surface ofthe first center portion 213A is abutted by the extension 214A1 of thesecond center portion 214A. With such a structure, the first and secondarms 213D and 214D are flush with each other, and the first and secondcenter portions 213A and 214A are nearly flush with each other.

[0158] Optionally, in order that the first and second lens sliders 213,214 take as little vertical space as possible, a longitudinal channel213G is formed in the upper surface of the first lens slider 213, whichaccepts either the screw head of screw 812 (connecting the second lensslider 214 to the second lens guiding piece 209), or the bottom of theextension 214A1 of the second lens slider 214 (also including the screwhead of the screw 812). In such a case, the longitudinal channel 213Gpermits the accepted portion to move in the longitudinal optical axisdirection without interfering with the first lens slider 213.

[0159] A hole 215A, penetrating the pressing plate 215 laterally(left toright), is formed on the pressing plate 215 on its front area, and asliding shaft 216 is inserted into the hole 215A and supported by thepressing plate 215, extending outward toward the right and left side ofthe shaft 216.

[0160] The right and left moving units 303 (as shown in FIG. 13) and 403(as shown in FIG. 16), supporting the right and left eyepiece opticalsystem, are respectively provided with engaging portions 303A1 and 403A1that engage with the moving shaft 216 so that the right and left movingunit 303 and 403 are supported slidably to slide not only in the lateraldirection along the lens moving shaft 216 but also to slide in theoptical axis direction together integrally with the moving shaft 216.

[0161] The lens moving shaft 216, penetrating the pressing plate 215 andbeing supported by the pressing plate 215, is disposed between the firstlens slider 213 and the second lens slider 214. As noted, the lenssliders 213 and 214 being disposed between the pressing plate 215 andthe bottom of the body 101.

[0162] The first and second lens sliders 213 and 214 are respectivelyconnected to the first and second lens guiding pieces 208 and 209, thefirst and second lens guiding pieces 208 and 209 being supported by thecam ring 207 and cam frame 210. As noted above, by virtue of the screw810 attaching the pressing plate 215 to the cam frame 210, the cam frame210 is integrally movable with the pressing plate 215 (along with thecam ring 207) in the direction of the optical axes. Accordingly, becauseof the connection to the cam ring 207 via the first and second lensguiding pieces 208 and 209, the first and second lens slider plate 213and 214 are movable along the direction of the optical axes togetherwith the pressing plate 215 (although the first and second lens sliderplate 213 and 214 are also movable in opposite directions along thedirection of the optical axes with respect to the pressing plate 215 forthe purpose of varying magnification).

[0163] As shown in FIGS. 9, 10 and 18A-18C, the body 101 of thesupporting unit 100 includes a first container 101G and a secondcontainer 101H, disposed along the optical axis with a spacetherebetween along the optical axis. The first container accommodatesthe focus arrangement ring 202, held in a manner to be rotatable aboutthe axis but unmovable along the axis direction. The second container101H accommodates the zooming ring 204, also rotatable about butunmovable along the axis direction.

[0164] In the structure mentioned above, when the zooming arrangementring 204 is rotated without rotating the focus arrangement ring 202, themain shaft 201 fixed to the zooming arrangement ring 204 is rotated, sothat the cam ring 207 fixed to the front end of the main shaft 201 isaccordingly rotated in the inside of the cam frame 210.

[0165] Consequently, when the zooming arrangement ring 204 is rotated,the first and second cam grooves 207D and 207E, provided on theperipheral outer surface of the cam ring 207, rotate with respect to thecam frame 210. The first and second lens guiding pieces 208 and 209,engaging the (zooming) balls 210B which cooperate with the rotation ofthe first and second cam grooves 207D and 207E, are moved along theaxial direction, guided by the guiding shafts 211 and 212. As mentionedabove, the first and second lens guiding pieces 208 and 209 move inreverse (opposite) direction with respect to each other when the zoomingarrangement ring 204 is rotated.

[0166] When the focus arrangement ring 202 is rotated without rotatingthe zooming arrangement ring 204, because there is no driving connectionbetween the focus arrangement ring 202 and the shaft 201, the shaft 201is not rotated. However, the (focusing) balls 203, engaging the helicalguiding groove 206A1, maintain their positions along the axis direction(by virtue of the mounting of the focusing ring 202 in the firstcontainer 101G of the body 100) but rotate about the axis while engagingthe helical guiding groove(s) 206A1 of the body 202A, which is integralwith the moving shaft 206. Accordingly, the moving shaft 206 and the camframe 210, integrally fixed to the shaft 206, are moved inside of thebody 101, along the direction of the optical axes and the axis of theshaft 201.

[0167] As mentioned above, the guiding grooves 206A include a firstgroove 206A11 with a long/wide (coarse) pitch, and a second groove206A12 with a short/narrow (fine) pitch, the first and second groove206A11 and 205A12 being connected with each other.

[0168] Accordingly, when the moving shaft 206 and the cam frame 210 movealong the optical axis with the balls 203 engaged in the first groove206A11, the amount of movement is much more than that with the balls 203in the second groove 206A12. Therefore, when engaging the first groove206, the lens barrels can be promptly drawn into the body, and whenengaging the second groove 206A12, the focal distance can be preciselyarranged by virtue of the narrow pitch.

[0169] The right lens barrel 300 and left lens barrel 400 are describedbelow with reference to FIG. 5.

[0170] The left and right assemblies have numerous similarities. Forexample, the right lens barrel 300 and left lens barrel 400 includeseveral, although not all, laterally symmetric elements with the samefunctions. Accordingly, the present description, where elements arelaterally symmetric, is restricted to the right side, and theexplanation for the left side is omitted. One skilled in the art willrecognize how the description for the right side may be related to thecorresponding elements on the left side. A consistent numbering schemeis used throughout this specification, such that when a part isdescribed for the right lens barrel in the “300” series, a correspondingpart on the left lens barrel is numbered similarly in the “400” series.Accordingly, the description with respect to the right side “300” seriesshould be considered to apply to those numbered elements of the leftside “400” series that appear in the drawings, but that have not beenspecifically described herein by such numbers. Of course, where thosenumbered elements of the left side “400” have been specificallydescribed, the description thereof should be considered. Those elementslaterally corresponding to each other, are designated with the samecombination of numbers and alphabetical designations.

[0171] As shown in FIG. 5, the right lens barrel 300 includes a rightframe 301, a right frame lid 302, a right movement unit 303, a righteyepiece cylinder 304, a right objective unit 305, a right prism unit306, a first lens unit 307, a second lens unit 308, a right eyepieceunit 309, a right outer unit 310 and other parts as described below.

[0172] The right frame lid 302, the right objective unit 305 and theright outer unit 310, being attached to the right frame 301, are mountedto the right slide plate 109 (refer to FIG. 7), movable in the lateraldirection together with the slide plate 109.

[0173] As shown in FIGS. 5 and 13, the right moving unit 303 is slidablewith respect to the right frame 301 along the optical axis. The rightprism unit 306 is provided at the front portion of the right moving unit303. A right eyepiece cylinder 304 is coupled to the rear portion of theright moving unit 303. The eye piece cylinder 304 (shown in FIGS. 5and14) includes an eyepiece unit 309 that is coupled to the rear portion ofthe right eyepiece cylinder 304. Moreover, as shown in FIGS. 5 and 14, afirst lens unit 307 and a second lens unit 308 are slidably disposedbetween the right moving unit 303 and the right eyepiece cylinder 304.

[0174] That is, the objective unit 305 is mounted to the right frame301, while the prism unit 306, the first lens unit 307, the second lensunit 308 and the eyepiece unit 309 are mounted to the right moving unit303. Therefore, the right moving unit 303 moves slidably with respect tothe right frame 301 along the optical axis, so that as the distancebetween the objective unit 305 and the right prism unit306, the firstlens unit 307, the second lens unit 308 and the eyepiece unit 309changes, accordingly, the focal distance is arranged.

[0175] Next, referring to FIGS. 8 and 12 to 14, the structure of theright lens barrel will be detailed.

[0176] As shown in FIG. 12, the right frame 301 is provided with aholding member 301B for holding the rear part of a right guiding shaft301A (at the center in the height direction of the )rear right side. Theunder part of the holding member 301B has a threaded hole 301C formedtherethrough, to which a screw is engaged for mounting the right frame301 to the right slide plate 109 (refer to the arrow “B”).

[0177] Referring to FIG. 8, the attachment of the right frame 301 to theright slide plate 109 is described below in detail.

[0178] Screws 820, 820 (front and rear) are screw coupled to a screwhole formed on the rear part of the right frame 301 (not shown) and to ascrew hole (not shown) formed on a frame lid 302 (shown in FIG. 12, anddiscussed below), via guiding grooves 102H1 and 102H2 of the supportingplate 102 and through holes 109C1 and 109C2. In such a structure, thehead of the screws 820 and 820 are accommodated in the guiding grooves102H1 and 102H2 on the supporting plate 102 without interfering thereto,thereby being laterally slidable.

[0179] Screw 821, 821 are screw coupled to screw holes formed on thefront and rear area of the right frame 301 via through holes 109Dl and109D2 (the front screw hole corresponds to the screw hole 301C; refer toarrow “B” in FIGS. 8 and 12). Here, the heads of the screw hole 821 and821 can be moved to and accommodated into notches 102J1 and 102J2 in theouter lateral side at front and rear of the supporting plate 102,without interfering thereto, thereby being laterally movable.

[0180] In such a structure, the right frame 301 is mounted on the rightslide plate 109 by means of the screws 820 and 821.

[0181] The left frame 401 is also similarly mounted to the left slideplate 110 (described below with reference to FIG. 15), describedimmediately below.

[0182] Screws 822, 822 are screw coupled to the screw hole (not shown)formed on the rear part of the left frame 401 and to the screw hole (notshown) formed on the frame lid 402 (discussed below), via guidinggrooves 102I1 and 102I2 of the supporting plate 102 and through hole110C1 and 110C2. In such a structure, the head of the screws 822 and 822are accommodated in the guiding groove I1 and 102I2 on the supportingplate 102I1 without interfering therewith, thereby being laterallyslidable.

[0183] Screw 823, 823 are screw coupled to screw holes formed on thefront and rear area of the left frame 401 via through holes 110D1 and110D2. Here, the heads of the screw hole 823 and 823 can be moved to andaccommodated into the notches 102Kl and 102K2, without interferingtherewith, thereby being laterally movable.

[0184] In such a structure, the left frame 401 is mounted on the leftslide plate 110 by means of the screws 822 and 823. The followingdescription returns to describing, the right lens barrel 300.

[0185] As shown in FIG. 12, the right frame 301 is provided with asupporting member 301E at the approximately center area in the heightdirection of the left rear portion of the right frame 301. forsupporting the rear portion of the left guiding shaft 301D (refer toarrow A).

[0186] The right frame 301 is provided with a threaded hole 301F formedapproximately in the center area in the height direction of the frontright wall, to which a screw 813 is screw coupled. The guiding shaft301A is intermediate the head of the screw 813 and the right wall forsupporting the guiding shaft.

[0187] As shown in FIG. 12, the right frame 301 has a threaded hole 301Gformed at the right upper portion of its front wall. A screw 814 isscrew coupled to the screw hole 301G via a through hole 302A, so thatthe right frame lid 302 is fixed to the front of the right frame 301.Further, the front end of the guiding shaft 301D (shown in FIG. 13) issupported by the right frame lid 302.

[0188] Moreover, a screw hole 302B is formed at the front portion of theright frame lid 302, to which a screw 815 is coupled via through hole310A22 that is provided on the front wall 310A2 of the right outerhousing 310A. Accordingly, the front portion of the right frame 301 isfixed to the front wall 310A2 of the outer housing 310A.

[0189] A screw 816 is screw coupled to an upper portion of the screwhole 301F of the right frame 301 via through hole 310A41 that is formedon the right wall 310A4 of the right outer housing 310A. Accordingly,the right side of the right frame 301 is fixed to the right wall 310A4of the right outer housing 310A.

[0190] A screw hole 301H is formed on the rear left side of wall of theright frame 301, to which a screw 817 is screw coupled via through hole310A32 that is formed on the rear wall 310A3 of the right outer housing310A. Accordingly, the rear side of the right frame 301 is fixed to therear wall 310A3 of the right outer housing 310A.

[0191] A hole 301J is formed on the rear left portion of the rear wall,opening rearward, to which an insertion projection 310C2 of the rightrear cover 310C (discussed below) is inserted.

[0192] The right outer housing 310 includes a right outer housing 310A,a right front cover 310B, a right rear cover 310C and other parts asdescribed herein.

[0193] As shown in FIG. 12, aright outer housing 310A includes a bottomwall 310A1, and a front wall 310A2, rear wall 310A3 and right side wall310A4 that extend from, respectively, the front, rear and right edge ofthe bottom wall 310A1.

[0194] An opening 310A21 is formed on the front wall 310A2 for theobjective optical system, and an opening 310A31 is formed in the rearwall 310A3 for the right eyepiece cylinder 304, including a third lens309C, to move therethrough.

[0195] A “V” shaped notch 310A51 is formed on the left edge and rearside of the upper wall 310A5 for accommodating the focus arrangementring 202 and the zooming arrangement ring 204.

[0196] The right front cover 310B is attached to the front side of thefront wall 310A2 via a double sided adhesive tape 310D, with the opening310B1 aligned with the opening 310B1.

[0197] The right rear cover 310C is attached to the rear side of therear wall 310A3 via a double sided adhesive tape 310E, with the opening310C1 aligned with the opening 310A31.

[0198] As shown in FIG. 5 and 12, the rear wall 310A3 of the right outerhousing 310A is provided with a through hole 310A33, corresponding tothe hole 301J of the right frame 301, through which the insertionprojection 310C2 of the right rear cover 310C is inserted into the hole301J, so that the right rear cover 310C is positioned with respect tothe right frame 310 and the right outer housing 310A.

[0199] A half-circular notch 310A11 is formed on the front left edge onthe bottom wall 310A1 of the right outer housing 310A. The half-circularnotch is formed in such a manner to avoid, i.e., not to interfere with,the diopter decorative ring 106.

[0200] As shown in FIG. 13, the objective unit 305 includes an objectiveframe 305A, an objective pressing ring 305B, an objective lens 305C andother parts as described below.

[0201] The objective frame 305A includes a cylindrical body 305A1, afirst holding portion 305A2 provided on the right side of the body305A1, a second holding portion 305A3 extending rearward from the leftside of the body 305A1, and an engaging portion 305A4 extending to theleft from the front area of the second holding portion 305A3.

[0202] The inner circumference of the body 305A1 is female threaded, andan outer circumference of the pressure ring 305B is male threaded. Theobjective lens 305C is intermediate the body 305A1 and the pressure ring305B, fixing the objective lens 305C securely therebetween.

[0203] The first holding portion 305A2 is provided slidably along theguiding shaft 301A (shown in FIG. 12), holding the guiding shaft 301A.

[0204] As shown in FIG. 13, the second holding portion 305A3 is providedwith a spindle hole 305A31, parallel to the optical axis, through whichthe guiding shaft 301D is slidably held. Thus, the objective frame 305Ais configured to be slidable along the guiding shafts 301A and 301D.

[0205] Therefore, the objective lens 305C, being fit in the objectiveframe 305A, can be positioned anywhere along the range of positionsdefined by the guiding shafts 301A and 301D, along their axes.

[0206] The engaging portion 305A4 is formed in a substantiallyrectangular shape, having two engaging walls 305A41 extending downwardat the front and rear edges thereof. The two engaging walls 305A41 areparallel to one another, extending in the lateral (left to right)direction.

[0207] The outer circumference surface of the diopter eccentric seat 107is intermediate, i.e., held between the two engaging walls 305A41, andwhen the diopter eccentric seat 107 is rotated, the outercircumferential surface of the diopter eccentric seat 107 iseccentrically rotated, moving the two engaging walls 305A41 abuttedthereto along the optical axis direction.

[0208]FIGS. 5 and 6 show that when the diopter eccentric seat 107 isrotated, the right objective frame 305A is moved along the optical axis,guided by the guiding shafts 301A, 301D, thereby arranging the locationof the objective lens 3 05C along the optical axis.

[0209] That is, the right objective frame 305A is moved with respect tothe right frame 301 by the rotation of the diopter eccentric seat 107(engaged with the engaging walls 305A41) about the shaft portion 106 ofthe diopter decorative ring 106.

[0210] As shown in FIG. 4, when the diopter decorative ring 106 isarranged so that the zero point “0” mark 106F is aligned with thereference mark 102 provided on the supporting plate 102, the rightobjective frame 305A is arranged to be situated at the center point inthe adjustable range with respect to the right frame 301. As previouslydescribed, the diopter decorative ring 106 and the diopter eccentricseat 107 are rotatably supported by the bottom lid 103 that is fixed onthe supporting plate 102.

[0211] That is, when the diopter eccentric seat 107 is rotated, theright objective frame 305A is moved along the guiding shafts 301A and301D (i. e., in the optical direction). The range of the diopterdecorative ring 106 and consequent adjustment positions are shown inFIGS. 25 through 27.

[0212] As shown in FIG. 13, the right moving unit includes a bottom wall303A that is rectangularly shaped, a rear wall 303B extends from therear edge of the bottom wall 303A, and a side wall 303C extends from theleft edge of the bottom wall 303A.

[0213] An engaging portion 303A1 is formed, extending laterally, on theleft edge at approximately the center thereof in the optical axisdirection. The engaging portion 303A1 engages the moving shaft 216(shown in FIG. 9) slidably, i.e., in a manner that is slidable along theshaft in the shaft direction. The engaging portion 303A1 can be seenclearly in FIGS. 25 through 27.

[0214] The rear wall 303B is provided with a circular hole 303B1 thecenter of the rear wall 303B. The bottom wall 303A is provided with abearing 303D at the right edge of the bottom wall 303A, for receivingthe guiding shaft 301A (shown in FIG. 12). The side wall 303C isprovided with a bearing 303E at the lower part of the side wall 303C,for receiving the guiding shaft 301D (shown in FIG. 13).

[0215] Therefore, the right moving unit 303 is movably supported by thebearings 303D and 303E, being guided respectively by guiding shafts 301Aand 301D along the optical axis.

[0216] As shown in FIG. 13, a prism unit 306 includes a holder 306A, anintermediating plate 306B, a holder lid 306C, a thin plate 306D, a firstprism 306E, a second prism (Dach or roof prism) 306F and so on.

[0217] The holder 306A includes an upper and bottom wall 306A1 and 306A2supporting the upper and bottom surfaces of the first prism 306E andsecond prism 306F, and a rectangularly shaped rear wall 306A3 connectingthe rear edges of the upper wall 306A1 and bottom wall 306A2.

[0218] The first prism 306E and the second prism 306F, constituting anerecting prism, are disposed in this order from the objective side,arranged to pass and erect light therethrough. The intermediating plate306B is disposed between an outcoming plane of the first prism 306E andan incident plane of the second prism 306F, so that the first and secondprism 306E and 306F are securely attached to an upper wall 306A1 and abottom wall 306A2 of the holder 306A (e.g., via an adhesive).

[0219] A holder lid 306C includes a front wall 306C1, and a right andleft side wall 306C2 and 306C3 extending toward the rear from the rightand left edges of the front wall, for connecting the edges of the upperwall 306A1 and the bottom wall 306A2 of the holder 306A1. The front wall306C1, opposing the incident surface of the first prism 306E, has anopening 306C11 formed therethrough, through which light passes.

[0220] The rearwall 306A3 of the holder 306A is also provided with anopening, through which the outcoming light from the second prism 306Fpasses.

[0221] The thin plate 306D is disposed between the rear side of the rearwall 306A3 of the holder 306A and the rear wall 303B of the moving unit303. In the center of the thin plate 306D, an opening 306D1 is formedfor passing light.

[0222] The rear wall 306A3 of the holder 306Ais provided with twothreaded holes 306A31 formed therein, opposing each other across theopening of the hole. Two screws 815 are screw coupled to the twothreaded holes 306Aa 31 of the rear wall 306A3 of the holder 306A, viaspring (or lock) washer 816, washer 817, the through hole 303B2 of therear wall 303B of the moving unit 303, and the through holes 306D2 ofthe thin plate 306D, so that the holder 306A is integrally fixed to themoving unit 303.

[0223] The rear wall 303B of the moving unit 303 has protrusions 303B3,which extend rearward and in which are formed threaded holes 303B31 inthe height direction therethrough.

[0224] As shown in FIG. 14, the right eyepiece cylinder 304 includes abottom wall 304A and an upper wall 304E, as well as a right side wall304B, a left side wall 304C and a rear wall 304D that extend,respectively from the right edge, left edge and the rear edge of thebottom wall 304A. The upper wall 304E is connected to the upper edges ofthe right side wall 304B, the left side wall 304C and the rear wall304Dd.

[0225] The front edges of the bottom wall 304A, the right wall 304B andthe upper wall 304E are formed to receive the rear wall 303B of themoving unit 303 (shown in FIG. 13), and are provided with respectivescrew holes 304F. Three screws 818 are screw coupled to the threadedholes 303B31 (shown in FIG. 13) formed on the corresponding protrusions303B3 of the rear wall 303B through respective through holes 304F, sothat the rear wall 303B is securely coupled to the right eyepiececylinder 304.

[0226] Therefore, the right eyepiece cylinder 304, the prism unit 306and the moving unit 303 are integrally coupled so as to be movable withrespect to the right frame 301 and the objective unit 305, guided by theguiding shaft 301A and 301D along the optical axis.

[0227] As shown in FIG. 14, two guiding shafts 311 are provided,parallel with each other along the optical axis, between the rearsurface of the rear wall 303B of the moving unit 303 (shown in FIG. 13)and the front surface of the rear wall 304D of the right eyepiececylinder 304 (shown in FIG. 13).

[0228] As shown in FIGS. 14 and 24A, 24B, the first lens unit 307includes a first lens frame 307A and a first lens 307B (together withthe left-side first lens 407B, corresponding to a first moving opticalsystem in the claims). FIGS. 24A and 24B show a detailed view of thefirst lens frame 307A and second lens frame 308A.

[0229] As shown in FIGS. 14 and 24A, the first lens frame 307A includesa body 307A1 (shaped cylindrically), an engaging arm 307A2 extendingfrontward from the lower part of the body 307A1, and two shaft holderarms 307A3 and 307A4 extending toward the rear, respectively, from theright and left edges of the body 307.

[0230] As shown in FIG. 14, the outer circumference of the first lens307B is held on the inner circumference of the body 307A1 of the firstlens frame 307.

[0231] As shown in FIGS. 14, 24A and 24B, an engaging protrusion 307A21is formed at the lower front end of the engaging arm 307A2 for engagingwith the channel groove 213D (shown in FIG. 9) that is provided on theright arm 213B of the first lens slide plate 213. The engagingprotrusion 307A21 (shown in FIG. 14) is engaged with the channel groove213D (shown in FIG. 9) so as to be movable laterally upon interpupillaryadjustment (in the longitudinal direction of the first arm 213B), butimmovable along the optical direction, that is, the first lens slider213 is connected to the first lens 307B via the first lens frame 307A.

[0232] As shown in FIGS. 14, 24A and 24B, the shaft holder arm 307A3 ofthe body 307A1 is provided with a shaft hole 307A31 to receive theguiding shaft 311 therethrough. The shaft holder arm 307A4 is providedwith a shaft hole 307A41 to receive the guiding shaft 311. The body307A1 is slidably supported by the guiding shafts 311 in the shaft holes307A31 and 307A41, slidable along the optical axis.

[0233] The second lens unit 308 includes a second lens frame 308A, asecond lens pressing ring 308B and a second lens 308C (together with theleft-side second lens 408C,corresponding to a second moving opticalsystem in the claims).

[0234] The second lens frame 308A includes a body 308A1 (shapedcylindrically), an engaging arm 308A2 extending toward the front fromthe lower edge of the body 308A1, a shaft holder 308A3 provided at theright edge of the body 308A1, and a shaft holder 308A4 provided at theleft edge of the body 308A1.

[0235] The inner circumference of the body 308A1 of the second lensframe 308A is formed to hold the outer circumference of the second lens308C. A female screw (threads) formed on the inner circumference isengaged to the male screw formed around the outer circumference of thepressing ring 308B, so that the second lens 308C is held by the body308A1 and the second lens pressing ring 308B.

[0236] The lower front end of the engaging arm 308A2 includes anengaging protrusion 308A21 formed thereon for engaging the concavedgroove 214 (shown in FIG. 9) provided on the left arm 214B of the secondlens slide plate 214. The engaging protrusion 308A21 (shown in FIG. 14)is engaged with the channel groove 214D(shown in FIG. 9) so as to bemovable laterally during interpupillary adjustment (in the longitudinaldirection of the second arm 214), but immovable in the opticaldirection.

[0237] As shown in FIGS. 14, 24A and 24B, a shaft hole 308A31 is formedon the shaft holder 308A3 of the body 308, into which the guiding shaft311 is inserted. Two shaft holes 308A41 and 308A42 (front and rear) areformed on the shaft holder 308A4, disposed in this order from theobjective side, and having a predetermined distance therebetween. Theguiding shaft 311 is inserted through each of the shaft holes 308A42 and308A42. Accordingly, the body 308A1 is slidably held by each guidingshafts 311 inserted into the shaft holders 308A31, 308A41 and 308A42,and is thereby slidable in the optical direction.

[0238] As shown in FIG. 14, the eyepiece unit 309 includes an eyepiecelens frame 309A, an eyepiece lens pressing ring 309B, an eyepiece lens(third lens) 309C and an eyepiece 309D.

[0239] The inner circumferential surface of the eyepiece lens frame 309Ais formed to hold the outer circumferential edge of the third lens 309C.The female thread 309A1, formed around the inner circumference, isscrewed by the male thread 309B1 of the outer circumferential edge ofthe pressing ring 309B, so that the third lens 309C is held between theeyepiece lens frame 309A and the eyepiece lens pressing ring 309B.

[0240] The rear wall 304D of the right eyepiece cylinder 304 has throughhole formed therein in the length (front to back) direction of the rearwall 304D,through which hole's inner circumference is provided a femalethread for providing an attaching portion 304Dl. A female thread of theattaching portion 304Dl is screwed by the male thread 309A2 formedaround the outer circumference of the eyepiece lens frame 309A, so thatthe eyepiece lens frame 309A is fixed to the attaching portion 304D1.

[0241] The upper surface of the bottom wall 304A of the right eyepiececylinder is provided with a receiving groove 304A1 extending along theoptical axis direction, for receiving the rear portion of the engagingarm 307A2 of the first lens frame 307A while permitting movement alongthe optical axis direction. Additionally, a receiving groove 304A2 isformed on the surface of the upper surface of the bottom wall 304A,extending parallel to and separated by a predetermined distance from thereceiving groove 304A1 mentioned above, for receiving the rear portionof the engaging arm 308A2 of the second lens frame 308A while the sameis moved moving.

[0242] As shown in FIGS. 22, 23, and 24A, 24B, the front portion of theengaging arm 307A2 of the first lens frame 307A and the front portion ofthe engaging arm 308A2 of the second lens frame 308A extend from thefront edge of the bottom wall 304Aa of the right eyepiece cylinder 304.

[0243] The under surface of the bottom wall 303A of the moving unit 303shown in FIG. 13 is provided with guiding grooves 303A2 and 303A3 (asshown in FIGS. 22 and 23) extending along the optical axis direction.The guiding groove 303A2 guides the front portion of the engaging arm307A2 of the first lens frame 307A, and the guiding groove 303A3 guidesthe front portion of the engaging arm 308A2 of the second lens frame308A. The engaging grooves 303A2, 303A3 can be seen clearly in FIG. 25(shown by double-dotted lines), FIG. 26 (showing the engagement of theengaging arms 307A3 and 308A2 thereto) and FIG. 27 (in which theengaging arm 308A2 is removed to show the guiding groove 303A3).

[0244] The engaging arms 307A2 and 308A2 are movably supported by themoving unit 303 and the right eyepiece cylinder 304, to move along theoptical axis.

[0245] By moving the first lens frame 307A and the second lens frame308A to approach to/move away from each other, the magnification of thetelescope optical system is varied. Here, the telescope optical systemincludes the objective lens 305C, the prism unit 306,the first lens307B, the second lens 308C and the third lens 309C.

[0246] That is, in this telescope system, the objective lens systemincludes the objective lens 305C, and the eyepiece lens system includesthe first lens 307B, the second lens 308C and the third lens 309C.Moving the first lens 307B to approach to/move away from the second lens308C in the optical direction varies the magnification of the telescopesystem.

[0247] As noted above, the left and right assemblies have numeroussimilarities, and in the following description, the description withrespect to the right side “300” series should be considered to apply tothose numbered elements of the left side “400” series that appear in thedrawings, but that have not been specifically described herein by suchnumbers.

[0248] Of course, where those numbered elements of the left side “400”series are specifically described, the elements differ from those of theright side, and the description thereof should be considered.Hereinbelow, the left frame 401 and the left objective frame 405 (of theelements in the left lens barrel 400), which are constituted differentlyfrom those of the right lens barrel 300, are described (for the purposeof clarity, some portions that are similar to those of the right lensbarrel 300 are also described).

[0249] As shown in FIG. 15, the left frame 401 is provided with a holder401B formed on the rear left portion at the center in the heightdirection, for holding the rear part of the left guiding shaft 401A,similar to the right frame 301 described above.

[0250] A threaded hole 401F is formed on the front left side wall of theleft frame 401 substantially at the center of the height direction. Ahead of a screw 813, screw-coupling into the hole 401F, and the leftside wall together hold the front portion of the guiding shaft 401A sothat the guiding shaft 401A is supported.

[0251] The lower part of the front left side wall of the left frame 401has a threaded hole 401C formed therein to be screw coupled for fixingthe left frame 401 to the left slide plate 110(shown in Fig, 8; refer tothe arrow “D”).

[0252] A holder 401E is formed on the rear right portion of the leftframe 401, at substantially the center in the height direction (refer toarrow “C”), for holding the rear portion of the guiding shaft 401D (FIG.16).

[0253] A threaded hole 401G is formed on the right upper part of thefront wall of the left frame 401. A screw 814 screw couples into thescrew hole 401G, through the through hole 402A of the left frame lid402, so that the left lid 402 is attached at the front of the left frame401. The left lid 402 holds the front of the guiding shaft 401D.

[0254] A threaded hole 402B is formed on the front of the left frame lid402, to which the screw 815 is coupled through the through hole 410A22provided on the front wall 410A2 of the left outer housing 410,.Accordingly, the front portion of the left frame 401 is fixed to thefront wall 410A2 of the left outer housing 410A via the left frame lid402.

[0255] A screw 816 is screwed into the threaded hole 401I formed abovethe upper portion of the threaded hole 401F of the left frame 401,through the through hole 410A41 formed on the left side wall 410A4 ofthe left outer housing 410A. Accordingly, the left side of the leftframe 401 is fixed to the left side wall 410A4 of the left outer housing410A.

[0256] A screw 817 is screwed into a threaded hole 401H formed on therear right wall of the left frame 401, through the through hole providedon the rear wall 410A3 of the left outer housing 410A, so that the rearpart of the left frame 401 is fixed to the rear wall 410A3 of the leftouter housing 410A.

[0257] An upper wall 401J, defined by and connected to the upperportions of the right and left side walls of the left frame 401, isapproximately rectangularly shaped. The front left side of the upperwall 401J is provided with a (vertically extending) circular throughhole 401K.

[0258] Under the circular hole 401K is formed an engaging portion 405A4formed on the left objective frame 405A, the engaging portion 405Aopposing the circular through hole 401K.

[0259] As shown in FIG. 16, the left objective frame 405A includes abody 405A1 shaped cylindrically, a first holding member 405A2 providedon the left side of the body 405A, and a second holding member 405A3provided on the right side of the body 405A1 and extending rearward.

[0260] The inner circumferential surface of the body 405A1 is formed tohold the outer circumference of the objective lens 405C, and is femalethreaded. The male threads formed around the outer circumference of theobjective pressing ring 405B are screwed into the female screw, so thatthe objective lens 405C is held by the body 405A1 and the objectivepressing ring 405B.

[0261] The first holding member 405A2 is formed to slidably hold theguiding shaft 401A (shown in FIG. 15), i.e., such that the leftobjective frame 405A is slidable along the axis direction of the guidingshaft 401A. In more detail, the first holding member 405A2 is providedwith two holders 405A21 and 405A22 projecting from the left edges of thebody 405A1. The holders 405A21 and 405A22 are formed to cover or bracketthe outer circumference of the guiding shaft 401A from the top andbottom sides (vertically) The upper holder 405A21 is provided with athreaded through hole 405A211, and the lower holder 405A22 is providedwith a threaded hole. The through hole 405A211, when the left objectiveframe 405 is assembled into the left frame 401, opens upward through anoblong circular hole 401L (refer to FIG. 15).

[0262] Accordingly, (before the screw 819 noted below is tightened) theguiding shaft 401A is held by the holders 405A21 and 405A22 so that thefirst holding member 405A2 is movable along the guiding shaft 401A.

[0263] The second holding member 405A3 is provided with a shaft hole405A31 formed to slidably receive the guiding shaft 401D along its axisdirection therein. Accordingly, the second holding member 405A3 isformed to hold the guiding shaft 401D, such that the left objectiveframe 405A is movable in the axis direction of the guiding shaft 401D.

[0264] Thus, the left objective frame 405A is held movably in theoptical axis direction by the guiding shafts 401A and 401D disposedparallel to each other.

[0265] Next, the arrangement of the objective lens at the production orassembly stage of the binocular, optionally using a calibration oradjustment jig (not shown), is briefly described.

[0266] The diopter of the right objective lens of the right lens barrel300 can be corrected for variation between an operator's left and righteyes after the binocular is assembled at any time. However, the locationof the left objective lens, once positioned at the production orassembly stage, is constructed to be permanently positioned (or atleast, not to be readily accessible to the ordinary operator).

[0267] A screw 819 is screwed into the threaded hole in the holder405A22 via a through hole 405A211 of the holder 405A21, and the holder405A21 and 405A22 clamp the guiding shaft 401A, so that the leftobjective frame 405A is fixed at the position along the optical axisdirection, held on the guiding shafts 401A and 401D of the leftobjective frame 405A. This fixing, as noted below, is optionallyperformed after manufacturing adjustment of the left-side diopter.However, the fixing may be in a reference position, i.e., withmanufacturing adjustment of the left-side diopter achieved by otherconventional means (e.g., adjustment of the lenses 405C within the frameby spacers, etc.).

[0268] Accordingly, the objective lens 405C, held on the left objectiveframe 405A, is positioned along on the axes of the guiding shafts 401Aand 401D with respect to the left frame 401, at which position theobjective lens 405C, within the left objective frame 405A, is securelyscrew-coupled by a screw 819 through the first holding member 405A2.

[0269] Review of the drawings will show that the left objective frame405A is not provided with structure corresponding to the engagementmember 305A engaging with the diopter arrangement eccentric seat 107 ofthe right objective frame 305A. This is because it is only necessary tohave movable one objective lens for the user to adjust diopter, in thiscase the right objective lens 305C. As noted, the objective lens 305C ofthe right lens barrel is provided with a mechanism for adjusting theposition in direction of the optical axis with respect to the rightframe 301 by rotating the diopter arrangement decorative ring 106, i.e.,rotating the diopter eccentric seat 107.

[0270] With respect to the left side barrel, the objective lens 405C, ispositioned with respect to the left frame 401 along the optical axis andsecurely fixed during the manufacturing process by the screw 819screw-coupled at the first holding member 405A2 (i.e., before shipment),before the outer housing 410A is attached to the left frame 401 at theproduction stage. Accordingly, adjustment of diopter on the left side byan observer during usual operation is not permitted or enabled after thebinocular is assembled. Accordingly, access by an operator, consumer oruser to the assembly-time diopter adjustment may be prevented,specifically by mounting the left outer housing 410A (as shown in FIG.15) to the left frame 401 and left frame lid 402 via screw 815, 816 and817, preventing access to the screw 819 and the channeled adjustmentgroove. Access to the screws 815 and 817 is prevented and the appearanceof the binocular is improved by securing the left rear cover 410B andleft front cover 410C via adhesive tape 410D and 410E, respectively.

[0271] As shown in FIG. 16, if correction of the left-side diopter is tobe performed before or in concert with the fixing operation, correctionmay be facilitated by providing an engagement portion for an externaltool or jig to engage. In such a case, an engaging portion 405A4 isprovided on the upper portion of the left side of the body 405A1 of theleft objective frame 405A. The engaging portion 405A4 includes twoprotrusions 405A41 and 405A42 disposed parallel to each other andextending perpendicular to the optical axis. A channeled adjustmentgroove is formed, defined by the two protrusions 405A41 and 405A42.

[0272] In order to adjust the left-side diopter, first, the diopter ofthe right telescope optical system is “zeroed” or centered (corrected tozero). The “zero point” mark 106F of the diopter decorative ring 106 ofthe diopter decorative ring 106 is aligned to the reference mark 102C(Refer to FIG. 4). By this alignment, the right objective frame 305Aislocated at the middle point of its adjustable range.

[0273] Next, as mentioned above, an eccentric tiparrangement/calibration jig (not shown) is used to arrange the locationof the left objective frame 405A of the left lens barrel 400 along theoptical axis direction. The position of the left objective frame 405A iscorrect when the diopter adjustment of the left and right side are equalto one another (since the user adjustment on the right side is zeroedduring the assembly-time adjustment of the left side). This equality canbe optically or mechanically measured or determined by an external tool;the manner of such determination is not critical.

[0274] Subsequently, the screw 819 (as shown in FIG. 16 is screwed andtightened (to a sufficient degree) into the threaded hole of the holder405A22 of the left objective frame 405A, fixing the left objective frame405A to the guiding shaft 401A, and fixing the location of the leftobjective frame 405 with respect to the left frame 401, along theoptical direction. Accordingly, the location of the left objective frame405A with respect to the left frame 401 along the optical axisdirection, that is to say the location of the objective lens, is fixedrelative to the left frame 401.

[0275] At this point, the user diopter adjustment on the right telescopeoptical system has been zeroed, i.e., in the middle of its adjustablerange. Moreover, the diopter adjustment of the left and right sides isequal. Lastly, the assembly-time diopter adjustment of the lefttelescope optical system is calibrated, complete and fixed at the equaland zeroed position.

[0276] In the condition mentioned above, the focus of the right and lefttelescope optical systems are matched so that the full dioptercorrection range (i.e., from zero to an equal degree in “+” and “−”directions) of the right lens barrel with respect to the right lensbarrel can be effectively assured along the optical direction. Theprocess is completed as noted above, i.e., the left outer housing 410A,left rear cover 410B and left front cover 410C are attached.

[0277] The operation of the user diopter correction in the right lensbarrel 300 can be seen by referring to FIGS. 14 and 17. First, anobserver observes a distant object by the left eye through the third(eyepiece) lens 409C (shown in FIG. 17) of the left lens barrel 400,focusing on the distant object so as to see the distant object mostclearly, by rotating the focus arrangement ring 202. Next, observing bythe right eye through the third (eyepiece) lens 309C (shown in FIG. 14)of the right lens barrel 300, the observer rotates the diopterdecorative ring 106 to see the object most clearly.

[0278] That is, rotating movement of the diopter correction decorativering 106, causing rotation of the diopter eccentric seat 107, isconverted to linear motion by engagement of the eccentrically seated (ormounted) disk-shaped body 107A and the channeled adjustment grooveformed by the engaging walls 305A41, 305A41, so that the location of theobjective lens 305 is arranged with respect to the right frame 301 fordiopter correction. As noted above, the range of the diopter decorativering 106 and consequent adjustment positions are shown in FIGS. 25through 27.

[0279] If the observer is the same upon subsequent uses of the binocular1000, there is no need to change the diopter after the user's initialcorrection. However, each operator can adjust for variation between thatoperator's left and right eyes.

[0280] The diopter correction decorative ring 106 is disposed on thecenter in the width direction near to the front end of the supportingplate 102, so that the thumb of either the right and left hands caneasily operate the diopter decorative ring 106 to rotate. Moreover, thethumb is already at, or is easily moved to, a sufficient distance, whilethe observer is focusing or zooming, from the diopter correctiondecorative ring 106, so that unintentional diopter operation by thethumb is prevented.

[0281] The first lens slider 213 and second lens slider 214 aredescribed hereinafter with respect to their relative positions andinteraction.

[0282] As noted, the first and second lens sliders 213 and 214 aredisposed in a space defined (on the bottom) by the supporting plate 102and (on top and left and right sides) by the body 101 and the telescopeoptical systems in the right and left lens barrels 300 and 400. Thefirst and second lens sliders 213 and 214 are shaped to move inside thespace mentioned above, along the axis direction, i.e., in the directionof the optical axes of the respective right and left telescope opticalsystems.

[0283] In further detail, a first center portion 213A of the first lensslider 213 and a second center portion 214A of the second lens slider214 are disposed in a space defined between the bottom of the body 101and the pressing plate 215, that is, between the bottom of the body 101and supporting plate 102. The first arm 213B of the first lens slider213 and a second arm 214B of the second lens slider 214 are disposed ina space defined between the right and left telescope optical systems andthe supporting plate 101.

[0284] In other words, each of the right and left telescope system hasan optical axis, each parallel to an optical axis direction (generallyany line parallel to the optical axes). A (left-right) lateral directioncan be defined as perpendicular to the optical axis direction andparallel to a plane including both optical axes (generally any lineextending orthogonally left-right). The supporting plate 102 ispositioned by a predetermined distance in a direction verticallyperpendicular to the right and left telescope optical systems, andextends in the optical axis and lateral directions, forming a spacebetween the right and left telescope optical systems and the supportingplate 102.

[0285] Accordingly, the first and second lens sliders 213 and 214 aredisposed in the spaces mentioned above, which reduces the necessaryspace in the height direction (vertically perpendicular to the opticalaxis direction), so that the size of the binocular can be minimized.

[0286] The movable range of the first and second lens sliders 213 and214 along the optical axis direction is described below.

[0287] As noted, the first and second lens guiding pieces 208 and 209move in opposite directions with each other along the optical axis,slidably disposed respectively on the left and right side of the camring 207 with a predetermined distance therebetween. The cam grooves207D, 207E and engagement of the balls 210B are structured such that themoving ranges of the first and second lens guiding pieces 208 and 209overlap in the longitudinal, optical axis direction. As the first andsecond lens guiding pieces 208 and 209 move, the first and second lenssliders 213 and 214 are moved to approach to/part from each other alongthe optical axis direction.

[0288] Although the moving ranges of the first and second lens guidingpieces 208 and 209 overlap in the optical axis direction, the movingranges of the channels 213D, 214D (which drive the lens frames 307A,308A, e.g., on the right side) and the moving ranges of the lens frames307A, 308A (e.g., on the right side) do not overlap in the optical axisdirection. The relative lengths of the first center portion 213A and theextension 214A1 “remove” the overlap, i.e., the first center portion213A is shortened with respect to the extension 214A1 to offset theright-side moving range of the channel 213D in front of the left-sidemoving range of the channel 214D.

[0289] Therefore, the space needed for the first and second lens sliders213 and 214 to is reduced, in the optical axis direction, compared withstructures in which an overlapping range is not provided. Accordingly,the size of the binocular in the length (front to back) direction isreduced.

[0290] The overall operation of the binocular 1000, configured suchmentioned above, is described below.

[0291] The binocular 1000 is, when stored or not used, as illustrated inFIGS. 1 and 2, that is, the right and left lens barrels 300 and 400 areclosed and the right and left eyepiece cylinders 304 and 404 areaccommodated in the body, or drawn in.

[0292] An operator holds the right and left lens barrel 300 and 400respectively with right and left hands, the thumbs of the right and lefthands supporting the right and left outer housing bottoms, and otherfingers of right and left hands hold the upper surface of the upper wallof respective right and left outer housing, therefore, holding the outerhousing between the fingers and thumbs.

[0293] The focus arrangement ring 202 and the zooming arrangement ring204 are disposed on the main shaft 201, adjacent to each other on thecenter of the binocular 1000 in the lateral direction, so that anyfinger (without the use of the thumbs) of the right and left hands caneasily rotate the two rings 202 and 204.

[0294] When the focus arrangement ring 202 is rotated by a finger, thearm 202A1 integrally formed on the body 202A (shown in FIG. 11),extending in the diameter direction, is also rotated, so that the(focusing/eyepiece extension) balls 203 engaged in the engagementportion 202A11 on the arm 202A1 move along the two-stage (coarse andfine) guiding grooves 206A1.

[0295] The protrusions 206C4, 206C5 (shown in FIG. 11) formed on theright and left portion of the flange 206C of the moving shaft 206 movealong the guiding grooves 101C11 and 101D11 (shown in FIG. 9) extendingalong the right and left wall 101 c and 101D.

[0296] Each protrusion 206C1 and 206C2 abuts the banks 101C12 and101D12, restricting the range of motion of the moving shaft 206 towardthe front, and each protrusion 206C4 and 206C5 abuts the rear wall 101G1of the body 101, restricting the range of motion to the rear.

[0297] As shown in FIG. 11, when the balls 203 move, engaging the firstgroove 206A11 (wide pitch), the moving amount of the moving shaft 206 bya rotation of the focus rotation ring 202, is larger than that whenengaging the second groove 206A12 (narrow pitch).

[0298] The moving shaft 206, coupled with the cam frame 210, isintegrally attached to the pressing plate 215 (shown in FIG. 9). Thepressing plate 215 is further attached integrally with the cooperatingshaft 216. Accordingly, cooperating with the movement of the movingshaft 206, the right and left moving units 306 (shown in FIGS. 5 and 13)and 406 (shown in FIG. 16) move rearward. Consequently, the right andleft eyepiece cylinders 304 (shown in FIGS. 5 and 14)and 404 (shown inFIGS. 5 and 17) project out the binocular. In such a condition, anoperator looks at an object of infinite distance through the botheyepiece 309 and 409 and laterally extends the right and left lensbarrels 300 and 400 to set an appropriate inter pupillary adjustment,such that the right and left images coincide for binocular vision.

[0299] As mentioned above, the right and left outer housing 310A (shownin FIGS. 5and 12) are respectively fixed to the right and left slideplates 109 and 110 (shown in FIGS. 6 through 8). Therefore, the rightand left lens barrels 300 and 400 move simultaneously and by the samedistance in the lateral direction, approaching to and moving away fromeach other, providing the observer an easy operation for interpupillaryadjustment. Moreover, due to the protrusions 103D extending from bottomlid 103 the slide plate 110 moves laterally with a given frictionalforce, affording a more comfortable operation feeling for theinterpupillary adjustment.

[0300] When setting interpupillary adjustment, the first lens frame 307Aand 407A and the second lens frame 308A and 408A are moved. The firstlens frame 307A and 407A and the second lens frame 308A and 408Arespectively engage the channel grooves 213D and 214D of the first andsecond arms 213B and 214B of the first and second lens sliders 213 and214. Therefore, the lens barrels 300 and 400, i. e., the right and lefttelescope optical systems move right and left direction symmetricallywith respect to the center of the lateral direction of the supportingplate 102.

[0301] As shown in FIGS. 20A through 20D, the (right-side) distancebetween the right guided portion 213E and the right edge of the channelgroove 213D equals the (left-side) distance between the left guidedportion 213F and the left edge of the channel groove 213D. The grooves213D, 213D respectively engage the engaging protrusions 307A21 and407A21 of the first lens frames 307A and 407A.

[0302] Similarly, as shown in FIGS. 21A through 21D, the (right-side)distance between the right guided portion 214E and the right edge of thechannel groove 214D equals the (left-side) distance between the leftguided portion 214F and the left edge of the channel groove 214D. Thegrooves 214D, 214D respectively engage the engaging protrusions 308A21and 408A21 of the second lens frames 308A and 408A.

[0303] In other words, the arm structures of the first and second lenssliders 213, 214 include right and left channels (213D, 214D) forengaging, at right and left engagement points (along 213D, 214D) theright (307A21, 308A21)and left portions (407A21, 408A21) of connectedmoving optical systems, and the distance between the right guided memberof each arm structure (213E, 214E) and the right engagement point alwaysequaling a distance between the left guided member of each armstructure(213F, 214F) and the left engagement point.

[0304] Accordingly, any stress arising at the first arm 213B due to theload of the first lens frames 307A and 407A equals the stress arising atthe second arm 214B due to the load of the second lens frames 308A and408A, on both of the right and left sides. Accordingly, the first andsecond lens sliders 213 and 214 move steadily and smoothly withoutpositional differences with respect to each other.

[0305] With reference to FIGS. 3, 5, and 6, as well as FIGS. 13 and 14,focus is arranged by rotating the focus arrangement ring 202. That is,the rotation of the focus arrangement ring 202 is converted into alinear movement of the right moving unit 303 (shown in FIG. 13), theright eyepiece cylinder 304 (shown in FIG. 14) and the eyepiece unit 309(shown in FIG. 14) with respect to the right objective frame 305A (shownin FIG. 13).

[0306] The prism unit 306 (shown in FIG. 13), the first lens 307 (shownin FIG. 14), the second lens 308 (shown in FIG. 14), and the third lens309 (shown in FIG. 14) move linearly with respect to the objective lens305C (shown in FIG. 13), so that the focus is arranged or adjusted.

[0307] The left lens barrel 400 also has the same operation for focusadjustment, a description of which is accordingly omitted.

[0308] Again, with reference to FIGS. 3, 5, and 6, and in detail shownin FIGS. 9-11, 14, 24A and 24B, magnification is varied by rotating thezooming arrangement ring 204. That is, by the rotation of the zoomingarrangement ring 204, the main shaft 201 (shown in FIG. 11) rotates,causing the rotation of the cam ring 207 with respect to the cam frame210. The first lens guiding piece 208 and the second lens guiding piece209, engaged respectively with the first cam groove 207D and the secondcam groove 207E via balls 210B in the cam ring 207, are moved in theopposite direction with each other.

[0309] Consequently, the first and second lens frame 307A and 308A (bothshown in FIG. 14), being respectively engaged with the first and secondlens slide plates 213 and 214 (shown in FIGS. 9 and 10), are moved toapproach/move away from each other (always moving in oppositedirections) by the same movement of the first and second lens guidingpieces 208, 209. The first and second lens 307B and 308B approach andmove away from each other so that the magnification of the telescopeoptical system is varied.

[0310]FIG. 22 shows a bottom view of the optical arrangement unit 200,in which the first and second lens sliders 213, 214 are moved apart fromeach other to a maximum distance, which arranges the telescope opticalsystems to the lowest magnification, and FIG. 23 shows a bottom view ofthe optical arrangement unit 200, in which the first and second lenssliders 213, 214 are closest to one another, which arranges thetelescope optical systems to the highest magnification. It should alsobe noted that FIGS. 25 through 27 also show varying levels of assemblyand cross section of the binocular, and may be referred to whererelevant to determine relative positions and relationships of elementsthat are hidden in other views.

[0311] As shown in FIGS. 22 and 23, the first lens 307B and the secondlens 308C approach and move away from each other, so that themagnification of the telescope systems varies. The right-side telescopeoptical system includes the objective lens 305C, prism unit 306, thefirst lens 307B the second lens 308C and the third lens 309C, and theleft-side optical system includes the corresponding elements on the leftside.

[0312] The left lens barrel 400 has the same operation for zoomingadjustment, and a description of the left lens barrel 400 is accordinglyomitted.

[0313] With reference to FIGS. 22 and 23, when magnification is variedby rotating the zooming arrangement ring 204, and thereby the cam ring207, the first lens guiding piece 208 (corresponding in position to thescrew 811, which secures the first lens slider 213 to the first lensguiding piece 208) and the second lens guiding piece 209 (correspondingin position to the screw 812, which secures the second lens slider 213to the second lens guiding piece 209)are moved in the opposite directionwith each other.

[0314] As shown in FIG. 22, the movement ranges of the first lensguiding piece 208 (reference screw 811) and the second lens guidingpiece 209 (reference screw 812) overlap. When the first and second lenssliders 213, 214 are apart from each other at a maximum distance, thefirst lens guiding piece 208 (reference screw 811) is closer to thefront of the binocular 1000 than the second lens guiding piece 209(reference screw 812). When the zooming arrangement ring 204 is rotatedsuch that the first and second lens sliders 213, 214 are moved towardeach other, the first lens guiding piece 208 and second lens guidingpiece 209 approach each other in the direction of the optical axes, passone another in the direction of the optical axes, and at the end of theadjustable range, reach the position shown in FIG. 23, in which thesecond lens guiding piece 209 (reference screw 812) is closer to thefront of the binocular 1000 than the first lens guiding piece 208(reference screw 811).

[0315] In this manner, as shown in FIGS. 22 and 23, the first and secondlens frame 307A and 308A (both shown in FIGS. 22 and 23), beingrespectively engaged with the first and second lens slide plates 213 and214, are moved to approach/move away from each other (always moving inopposite directions) by the same amount of movement as the first andsecond lens guiding pieces 208, 209, varying the magnification of thetelescope optical systems.

[0316] The optical arrangement structure 200 includes the main shaft201, the zooming arrangement ring 204, the cam ring 207, the first lensguiding piece 208, the second lens guiding piece 209, the cam frame 210,the guiding piece shafts 211, 212, the first lens slider 213 and thesecond lens slider 214, which are included in the optical arrangementstructure. As previously described, the elements of the opticalarrangement structure 200 are mounted on the supporting plate 101 suchthat the optical arrangement structure 200 and its component elementsare not movable in the lateral. i.e., left-to-right, direction.

[0317] Variations on the structure of the disclosed embodiment fallwithin the scope of the invention. For example, the supporting plate 102is illustrated as disposed under the two telescope optical systems.However, the invention extends to embodiments where the supporting plate102 is disposed above the two telescope optical systems.

[0318] Further, the movement pattern of the moving optical systemsaccording to the invention, as determined by the mechanisms driving theoptical systems, are not restricted to a movement pattern in which theoptical systems move in opposite directions to one another. For example,the first lens can be arranged to move linearly and constantly, whilethe second lens is arranged to move either nonlinearly or at a multipleof the movement rate of the first lens such that the first and secondlenses separate from one another while nonetheless moving in the samedirection.

[0319] Moreover, the moving optical system is not restricted to theelements of the eyepiece optical system, but can include the objectiveoptical system, optionally with a field stop. That is, the movingmechanisms and movements of the invention apply at least to anymechanism that moves a field stop along the optical axis direction,according to the movement of the eyepiece focus, as the magnificationvaries.

[0320] The moving optical system is also applicable to a focusarrangement. For example, the moving optical system as set forth hereinis applicable at least to a binocular provided with a so-called“floating” focus arrangement method, in which the objective opticalsystem is divided into a plurality of lens groups for moving along theoptical axis direction under different conditions, which prevents thedeterioration of the observed image resulting from a change inaberrations of the telescope optical system when the distance of theobserved objection changes.

[0321] As described and claimed, both of magnification variation andfocusing are considered to be an optical change in the image, and amovable optical system may share optical elements with another movableoptical system in the same telescope system (e.g., as in the presentinvention, where the focusing and magnification optical systems shareoptical elements). The lenses and prisms are considered opticalelements, as would be diffraction elements, Fresnel elements, filters orany other element that alters optical characteristics.

[0322] Further, where a first movable optical system and second movableoptical system are recited, such a recitation does not preclude theinclusion of third and subsequent movable optical systems withoutdeparting from the intended scope of the invention thereof. Wheremovement in the optical axis direction is recited, such movement is notnecessarily specified to be front-to-back or back-to-front, unless sospecified. Similarly, where a part or structure is specified to be in adirection that is vertically perpendicular with respect to another partor structure, such direction is not necessarily above or below unless sospecified. Although the present specification uses “first and second”with respect to various systems, recitations of “first” and “second” inthe claims do not necessarily correspond thereto, and may be reversed,the relevant corresponding structure in the specification beingdetermined by the recitations taken in context.

[0323] The binocular according to the present invention providesbeneficial effects at least as follows.

[0324] The present invention reduces the space occupied by an opticalarrangement unit that moves the magnification varying lenses of theright and left telescope optical systems, and occupies a much smallerspace than conventional zooming mechanism for a binocular, suitable fora small size binocular.

[0325] Although the above description sets forth particular embodimentsof the present invention, modifications of the invention will be readilyapparent to those skilled in the art, and the inventors expressly intendthat the scope of the invention, as well as elements necessary for theinvention to function, be determined solely by the appended claims.Changes may be made, within the purview of the appended claims, asoriginally submitted and as amended, without departing from the scopeand spirit of the invention in its aspects. No one or more of thepreceding described elements is critical or necessary to the operationof the invention, except as explicitly described herein. Although theinvention has been described with reference to particular means,materials and embodiments, the inventors do not intend that theinvention is to be limited to the particulars disclosed; rather, theinvention extends to all equivalent and/or insubstantially differentstructures, methods and uses such as are within the scope of theappended claims, as originally submitted and as amended.

[0326] The present disclosure relates to subject matter contained inJapanese Patent Application No. 2000-082079, filed on Mar. 23, 2000,which is expressly incorporated herein by reference in its entirety.

What is claimed is:
 1. A binocular, comprising: an outer body housing; a right lens barrel and a left lens barrel; a right telescope system and a left telescope optical system, respectively accommodated in said right and left lens barrels, each of said right and left telescope system having an optical axis parallel to an optical axis direction of the binocular, a lateral direction of the binocular being perpendicular to the optical axis direction and parallel to a plane including both optical axes; each of said right and left telescope optical systems including a first movable optical system and a second movable optical system, each of said first and second movable optical systems including optical elements movable along an optical axis direction toward and away from one another so that an image observed is optically changed; a first guiding member that guides and moves together optical elements of said first movable optical system of each of said right and left telescope optical systems in the optical axis direction; a second guiding member that guides and moves together optical elements of said second movable optical system of each of said right and left telescope optical systems in the optical axis direction; an optical arrangement structure that moves said first and second movement member in the optical axis direction, wherein said arrangement structure is disposed between said right and left lens barrels; and a supporting plate positioned by a predetermined distance in a direction vertically perpendicular to said right and left telescope optical systems, said supporting plate extending in the optical axis direction and in the lateral direction, forming a space between said right and left telescope optical systems and said supporting plate, said first and second movement members being disposed within and moved in the optical axis direction within said space.
 2. The binocular according to claim 1 , wherein said right and left lens barrels are further movable in the lateral direction by symmetric distances with respect to a center line of said supporting plate.
 3. The binocular according to claim 1 , wherein said first guiding member has a first arm structure including right and left arms respectively extending in the lateral direction rightward and leftward, respectively engaging said right and left first moving optical systems, and said second guiding member has a second arm structure including right and left arms respectively extending in the lateral direction to rightward and leftward, respectively engaging said right and left second moving optical systems.
 4. The binocular according to claim 3 , wherein said right arm and said left arm of said first arm structure are respectively parallel to said right arm and said left arm of said second arm structure, said first arm structure and said second arm structure are movable to positions where a portion of said first movement member is substantially flush to a portion of said second movement member, and said first movement member and said second movement member being arranged to move without interference.
 5. The binocular according to claim 3 , wherein said arrangement structure includes: a body positioned approximately equal distances from said right and left lens barrels in said lateral direction, the body including a first connecting member and a second connecting member, said first guiding member including a first center member between said first arms, said first center member connecting to said first connecting member, said second guiding member includes a second center member between said second arms, said second center member connecting to said second connecting member, and each of said first and second connecting members moving along said optical axis direction.
 6. The binocular according to claim 5 , wherein said arrangement structure includes a guide, said first center member and second center members each including a right guided member and a left guided member that are guided by said guide for slidably moving along said optical axis direction.
 7. The binocular according to claim 6 , wherein said first arm structure includes right and left channels for engaging, at right and left engagement points, right and left portions of said first moving optical system, a distance between said right guided member of said first arm structure and said right engagement point always equaling a distance between said left guided member of said first arm structure and said left engagement point.
 8. The binocular according to claim 7 , wherein said second arm structure includes right and left channels for engaging, at right and left engagement points, right and left portions of said second moving optical system, a distance between said right guided member of said second arm structure and said right engagement point always equaling a distance between said left guided member of said second arm structure and said left engagement point.
 9. The binocular according to claim 3 , wherein said first moving optical system is connected to said first arm member and is movable along said first arm member in the lateral direction, and said second moving optical system is connected to said second arm member and is movable along said second arm member in the lateral direction.
 10. The binocular according to claim 1 , wherein at least one of said first and second moving optical systems includes optical elements forming an eyepiece optical system. 